| Date | Panel | Item | Activity | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Intellectual disability syndromic and non-syndromic v1.164 | PTPN1 |
Zornitza Stark gene: PTPN1 was added gene: PTPN1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: PTPN1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: PTPN1 were set to 39986310 Phenotypes for gene: PTPN1 were set to Type 1 interferonopathy of childhood, MONDO:0957408, PTPN1-related Review for gene: PTPN1 was set to GREEN Added comment: 12 patients from 11 families with phenotype characterised by subacute loss of skills following initially normal development, spastic dystonia, bulbar involvement, preserved head circumference, and an absence of seizures. The observation of enhanced type 1 IFN signalling in patient blood and CSF, and of increased levels of CSF neopterin suggests that PTPN1 haploinsufficiency can be classified as a novel type 1 interferonopathy. Features apparently distinguishing PTP1B-related encephalopathy from Aicardi-Goutières syndrome are a later age at onset (nine of 12 cases in cohort presenting beyond 18 months of age), notable bulbar involvement manifesting as difficulties with swallowing and expressive speech, and cerebral atrophy as the predominant neuroradiological sign. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v1.90 | SVBP | Zornitza Stark edited their review of gene: SVBP: Added comment: PMID 39412222: 6 individuals from 3 families with spastic paraplegia and the same homozygous missense (L49P). Presented from birth or childhood with DD/ID and spastic paraplegia. Additional features: verbal apraxia, axonal neuropathy, ataxia, nystagmus, epilepsy, and aggressive behaviour. Brain MRIs were performed in 3 individuals and showed thinning of the corpus callosum, cerebellar atrophy, and ventriculomegaly; frontal ventricular hyperintensities suggestive of the 'ear of the lynx' sign in 2. Three individuals had a history of cancer of epithelial origin, including adenocarcinoma (patient 1), colonic tubular adenoma (patient 2), and breast cancer (patient 3).; Changed publications: 39412222; Changed phenotypes: Neurodevelopmental disorder with ataxia, hypotonia, and microcephaly, MIM #618569, Spastic paraplegia 94, autosomal recessive, MIM# 621150 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.6814 | IFIH1 | Zornitza Stark Phenotypes for gene: IFIH1 were changed from to IFIH1-related type 1 interferonopathy MONDO:0700262 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.6665 | TSHZ3 |
Bryony Thompson gene: TSHZ3 was added gene: TSHZ3 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: TSHZ3 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: TSHZ3 were set to 27668656; 34919690; 36553458; 39420202 Phenotypes for gene: TSHZ3 were set to congenital anomaly of kidney and urinary tract MONDO:0019719 Review for gene: TSHZ3 was set to AMBER Added comment: More evidence for the gene-disease association is required PMID: 27668656 - TSHZ3 is included in the region deleted in chromosome 19q13.11 Deletion Syndrome, which includes intellectual disability and behavioural issues, congenital anomalies of the kidney and urinary tract (CAKUT) PMID: 34919690 - haploinsufficient mouse model leads to kidney defects PMID: 36553458 - heterozygous frameshift variant c.119_120dup p.Pro41SerfsTer79 in a case with intellectual disability, behavioural issues, pyelocaliceal dilatation, and mild urethral stenosis. PMID: 39420202 - 12 CAKUT patients from 9/301 (3%) families carried 5 different rare heterozygous TSHZ3 missense variants. However, 1 of the variants (p.Ser58Gly) present in 5 of the families is more common in gnomAD v4.1 than you would expect for a dominant disease including 5 homozygotes (1,408/1,612,114 alleles, 5 hom, AF=0.0008734). The authors state this is not unexpected in a condition, such as CAKUT. However, the different missense variants are inherited from unaffected parents in at least 2/9 families (there was no phenotype information available for an additional 3 parents). Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.6222 | IFIH1 | Sangavi Sivagnanasundram reviewed gene: IFIH1: Rating: GREEN; Mode of pathogenicity: Loss-of-function variants (as defined in pop up message) DO NOT cause this phenotype - please provide details in the comments; Publications: 20301648, 25620204; Phenotypes: IFIH1-related type 1 interferonopathy MONDO:0700262; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.6134 | ATP6V1C1 |
Zornitza Stark gene: ATP6V1C1 was added gene: ATP6V1C1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ATP6V1C1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: ATP6V1C1 were set to 39210597 Phenotypes for gene: ATP6V1C1 were set to neurodevelopmental disorder MONDO:0700092, ATP6V1C1-related Review for gene: ATP6V1C1 was set to RED Added comment: 1x de novo missense p.Glu289Lys (absent in v4 gnomad). Manual inspection of IGV found the dad was mosaic 7% VAF and he shared some of the clinical features (minor digit anomalies). Some functional studies using patient fibroblasts were performed, demonstrating similar effects as known pathogenic variants in ATP6V1B2. - lysosomal morphology - autophagic flux dysregulation - increased acidification of lysosome borderline red/amber Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.6123 | REPS2 |
Mark Cleghorn gene: REPS2 was added gene: REPS2 was added to Intellectual disability syndromic and non-syndromic. Sources: Other Mode of inheritance for gene: REPS2 was set to X-LINKED: hemizygous mutation in males, biallelic mutations in females Phenotypes for gene: REPS2 were set to complex neurodevelopmental disorder MONDO:0100038; Cerebral palsy HP:0100021 Penetrance for gene: REPS2 were set to unknown Review for gene: REPS2 was set to AMBER Added comment: REPS2 Hao Hu, Guangzhou Women and Children’s MC ESHG talk 1/6/24, unpublished Proposed X-linked cerebral palsy + NDD gene 4 unrelated males with predicted deleterious hemizygous REPS2 variants, 2 PTC, 2 missense. 2 de novo, 2 maternally inherited Phenotypes: 2 w CP + moderate ID/ASD, 2 w NDD NOS Variants described: c.1050_1052delGAA;p.K351del c.1040T>C; p.I347T c.962C>G; p.S321C c.1736delA; p.N579Tfs*17 In vitro assay of above 4 variants suggest reduced REPS2 protein stability Zebrafish model: REPS2 expressed in neuronal cells, REPS2 knock down have reduced motor activity and abN neuronal morphology Mouse model hemizygous w one of above variants (not specified): reduced performance in cognitive tasks, abnormal neuronal migration pattern on post mortem examination Mechanism may relate to dopamine signalling? Sources: Other |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.6021 | ERF | Chirag Patel Classified gene: ERF as Green List (high evidence) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.6021 | ERF | Chirag Patel Gene: erf has been classified as Green List (High Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.6020 | ERF | Chirag Patel reviewed gene: ERF: Rating: GREEN; Mode of pathogenicity: None; Publications: PMID: 38824261; Phenotypes: Noonan syndrome-like with or without craniosynostosis; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted; Current diagnostic: yes | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5755 | PLXNB2 | Zornitza Stark Phenotypes for gene: PLXNB2 were changed from Amelogenesis imperfecta MONDO:0019507, PLXNB2 -related; Sensorineural hearing loss disorder MONDO:0020678, PLXNB2 -related to Syndromic disease MONDO:0002254, PLXNB2 -related | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5745 | FRYL |
Ain Roesley gene: FRYL was added gene: FRYL was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: FRYL was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: FRYL were set to 38479391 Phenotypes for gene: FRYL were set to neurodevelopmental disorder MONDO:0700092, FRYL-related Review for gene: FRYL was set to GREEN gene: FRYL was marked as current diagnostic Added comment: 14 individuals, all de novo except 1x duo testing (not present in tested father) 5x missense + 8x fs/stopgain + 1x canonical splice 13/13 with ID/DD (1x deceased) 4/14 seizures 7/14 with cardiac anomalies such as PDA, TOF, VSD, dextrocardia 1x also has a de novo fs variant in SF3B4 1x also has a de novo stop gain variant in SDHA functional studies using flies were performed Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5741 | PLXNB2 |
Chirag Patel gene: PLXNB2 was added gene: PLXNB2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: PLXNB2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PLXNB2 were set to PMID: 38458752 Phenotypes for gene: PLXNB2 were set to Amelogenesis imperfecta MONDO:0019507, PLXNB2 -related; Sensorineural hearing loss disorder MONDO:0020678, PLXNB2 -related Review for gene: PLXNB2 was set to GREEN gene: PLXNB2 was marked as current diagnostic Added comment: 8 individuals from 6 families with core features of amelogenesis imperfecta and sensorineural hearing loss. Intellectual disability, ocular disease, ear developmental abnormalities and lymphoedema were also present in multiple cases. WES and WGS identified biallelic pathogenic variants in PLXNB2 (missense, nonsense, splice and a multiexon deletion variants). Variants segregated with disease. PLXNB2 is a large transmembrane semaphorin receptor protein, and semaphorin-plexin signalling controls cellular interactions that are critical during development as well as in adult life stages. Plxnb2 expression was detected in differentiating ameloblasts in mice. Human phenotype overlaps with that seen in Plxnb2 knockout mice. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5729 | USP14 |
Zornitza Stark gene: USP14 was added gene: USP14 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: USP14 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: USP14 were set to 38469793; 35066879 Phenotypes for gene: USP14 were set to Syndromic disease MONDO:0002254, USP14-related Review for gene: USP14 was set to AMBER Added comment: AMBER rating as two of the families had affected fetuses, one had a severely affected newborn, and fourth had a progressive course: none fit well with ID, though there's likely to be a continuum. PMID 35066879: 3 fetuses from 2 different branches of a consanguineous family, presenting with distal arthrogryposis, underdevelopment of the corpus callosum, and dysmorphic facial features. Exome sequencing identified a biallelic 4-bp deletion (c.233_236delTTCC; p.Leu78Glnfs*11) in USP14, and sequencing of family members showed segregation with the phenotype. Ubiquitin-specific protease 14 (USP14) encodes a major proteasome-associated deubiquitinating enzyme with an established dual role as an inhibitor and an activator of proteolysis, maintaining protein homeostasis. Usp14-deficient mice show a phenotype similar to lethal human multiple congenital contractures phenotypes, with callosal anomalies, muscle wasting, and early lethality, attributed to neuromuscular junction defects due to decreased monomeric ubiquitin pool. RT-qPCR experiment in an unaffected heterozygote revealed that mutant USP14 was expressed, indicating that abnormal transcript escapes nonsense-mediated mRNA decay. PMID 38469793: biallelic USP14 variants in four individuals from three unrelated families: one fetus, a newborn with a syndromic NDD, and two siblings affected by a progressive neurological disease. Specifically, the two siblings from the latter family carried two compound heterozygous variants c.8T>C p.(Leu3Pro) and c.988C>T p.(Arg330*), while the fetus had a homozygous frameshift c.899_902del p.(Lys300Serfs*24) variant and the newborn patient harbored a homozygous frameshift c.233_236del p.(Leu78Glnfs*11) variant. The fetus and the newborn had extensive brain malformations. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5509 | ZBTB47 |
Elena Savva gene: ZBTB47 was added gene: ZBTB47 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ZBTB47 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: ZBTB47 were set to 37743782 Phenotypes for gene: ZBTB47 were set to Neurodevelopmental disorder (MONDO#0700092), ZBTB47-related Review for gene: ZBTB47 was set to GREEN Added comment: PMID 37743782: - 5 patients with de novo missense, 4/5 have a recurring p.Gly477Lys. Probands have intellectual disability (5/5), seizures (5/5), hypotonia (5/5), gait abnormalities, and variable movement abnormalities (5/5). - Missense variants are positioned close to His and Cys residues involved in forming C2H2 zinc fingers. - No functional studies performed - Minimal PTCs in gnomAD Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5311 | NAA30 |
Sarah Pantaleo gene: NAA30 was added gene: NAA30 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: NAA30 was set to Unknown Publications for gene: NAA30 were set to PMID: 37387332 Penetrance for gene: NAA30 were set to unknown Review for gene: NAA30 was set to RED Added comment: Report a de novo heterozygous NAA30 nonsense variant c.244C>T, p.(Gln82*) in a 5yo boy with GDD, ASD, hypotonia, seizures, tracheal cleft and recurrent respiratory infections. Seizures resolved after two weeks of life. Family history of ASD in older sister. Epilepsy in mother, childhood onset. Biochemical studies performed to assess the functional impact of the premature stop codon on catalytic activity. The variant was found to completely disrupt N-terminal acetyltransferase activity using an in vitro acetylation assay. Variant de novo, “in a gene sensitive to loss of heterozygosity”. Limitation of study - have not established whether this gene variant acts in a dominant or recessive manner. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5239 | NSUN6 |
Michelle Torres gene: NSUN6 was added gene: NSUN6 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: NSUN6 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: NSUN6 were set to 37226891 Phenotypes for gene: NSUN6 were set to neurodevelopmental disorder MONDO:0700092, NSUN6-related Review for gene: NSUN6 was set to AMBER Added comment: Three unrelated consanguineous families with developmental delay, intellectual disability, motor delay, and behavioral anomalies. WES detected homozygous variants: - p.(Leu9Glufs*3): even though authors say is is predicted to cause NMD, it actually is NMD escape. No further studies were performed. A deceased affected sibling and parents were NOT tested. - p.(Asp323Asn): Shown to result in a misfolded protein. Methylation assay showed mutant could not catalyze m5C deposition in transcribed tRNACys and tRNAThr substrates in vitro. One of the parents and both unaffected siblings were shown to be carriers. - p.(Glu441Profs*15): truncation (full protein is 470aa) which would result in loss of residues involved in recognition and methylation. Shown to result in a misfolded protein. Parents were shown carriers. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5182 | DPYSL2 |
Achchuthan Shanmugasundram gene: DPYSL2 was added gene: DPYSL2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: DPYSL2 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: DPYSL2 were set to 27249678; 35861646 Phenotypes for gene: DPYSL2 were set to intellectual disability, MONDO:0001071; Aplasia/Hypoplasia of the corpus callosum, HP:0007370 Review for gene: DPYSL2 was set to AMBER Added comment: This gene should be rated AMBER, as it has been associated with intellectual disability (ID) from two unrelated cases displaying monoallelic variants in DPYSL2/ CRMP2, and supported by functional studies. However, the evidence is not sufficient for green rating as there are variants reported in other (but different) genes in the two patients. PMID:35861646 reported two cases identified with heterozygous variants (patient1: c.1693C>T (p.Arg565Cys); patient 2: c.42C>A (p.Ser14Arg). These patients had overlapping phenotypes including dysmorphic features, severe global developmental delay and hypoplasia of the corpus callosum. In addition, patient 2 was bed-ridden and could not roll out and had a history of myoclonic seizures and status epilepticus. It should be noted that patient 1 is compound heterozygous for 2 missense variants in the EFCAB5 gene and was hemizygous for a maternally inherited missense variant in the GPKOW gene and patient 2 had 1 de novo missense variant in the COBLL1 gene and was compound heterozygous for 2 missense variants in the POTEF gene. The severity of the phenotypes between the two cases differs significantly and the additional variants may have possibly contributed to this phenotype. Brain-specific Crmp2 knockout mice display neuronal development deficits and behavioural impairments associated with hypoplasia of the corpus callosum. In addition, functional studies performed in zebrafish and cell lines that the CRMP2 variants lead to the loss-of-function of CRMP2 protein and can cause intellectual disability. This gene has not yet been associated with relevant phenotypes either in OMIM or in Gene2Phenotype. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4868 | C18orf32 |
Naomi Baker gene: C18orf32 was added gene: C18orf32 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: C18orf32 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: C18orf32 were set to PMID:35107634 Phenotypes for gene: C18orf32 were set to Neurodevelopmental disorder (MONDO:0700092), C18orf32-related Review for gene: C18orf32 was set to RED Added comment: Two siblings reported as affected, although sequencing only performed in one sibling, with homozygous loss-of-function variant identified. Clinical presentation included developmental delay, recurrent lower respiratory tract infections, sparse rough hair, roving eye movements, hypotonia, bilateral ankle contractures and inverted nipples. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4818 | PAN2 |
Naomi Baker gene: PAN2 was added gene: PAN2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: PAN2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PAN2 were set to PMID:35304602; 29620724 Phenotypes for gene: PAN2 were set to Syndromic disease MONDO:0002254 Review for gene: PAN2 was set to GREEN Added comment: PMID:35304602 reports five individuals from 3 families with biallelic (homozygous) loss-of-function variants. Clinical presentation incudes mild-moderate intellectual disability, hypotonia, sensorineural hearing loss, EEG abnormalities, congenital heart defects (tetralogy of Fallot, septal defects, dilated aortic root), urinary tract malformations, ophthalmological anomalies, short stature with other skeletal anomalies, and craniofacial features including flat occiput, ptosis, long philtrum, and short neck. PMID:29620724 reports one individual with biallelic (homozygous) loss-of-function variant who presented with global developmental delay, mild hypotonia, craniosynostosis, severe early-onset scoliosis, imperforate anus, and double urinary collecting system. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4507 | CHKA |
Konstantinos Varvagiannis gene: CHKA was added gene: CHKA was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: CHKA was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: CHKA were set to 35202461 Phenotypes for gene: CHKA were set to Abnormal muscle tone; Global developmental delay; Intellectual disability; Seizures; Microcephaly; Abnormality of movement; Abnormality of nervous system morphology; Short stature Penetrance for gene: CHKA were set to Complete Review for gene: CHKA was set to GREEN Added comment: Klöckner (2022 - PMID: 35202461) describe the phenotype of 6 individuals (from 5 unrelated families) harboring biallelic CHKA variants. Shared features incl. abnormal muscle tone(6/6 - hypertonia or hypotonia, 3/6 each), DD/ID (6/6,severe in 4, severe/profound in 2), epilepsy (6/6 - onset: infancy - 3y2m | epileptic spasms or GS at onset), microcephaly (6/6), movement disorders (3/6 - incl. dyskinesia, rigidity, choreoatetotic movements). 2/5 individuals exhibited MRI abnormalities, notably hypomyelination. Short stature was observed in 4/6. Eventual previous genetic testing was not discussed. Exome sequencing (quattro ES for 2 sibs, trio ES for 1 individual, singleton for 3 probands) revealed biallelic CHKA variants in all affected individuals. Sanger sequencing was performed for confirmation and segregation studies. Other variants (in suppl.) were not deemed to be causative for the neurodevelopmental phenotype. 3 different missense, 1 start-loss and 1 truncating variant were identified, namely (NM_0012772.2): - c.421C>T/p.(Arg141Trp) [3 hmz subjects from 2 consanguineous families], - c.580C>T/p.Pro194Ser [1 hmz individual born to consanguineous parents], - c.2T>C/p.(Met1?) [1 hmz individual born to related parents], - c.14dup/p.(Cys6Leufs*19) in trans with c.1021T>C/p.(Phe341Leu) in 1 individual. CHKA encodes choline kinase alpha, an enzyme catalyzing the first step of phospholipid synthesis in the Kennedy pathway. The pathway is involved in de novo synthesis of glycerophospholipids, phosphatidylcholine and phosphatidylethanolamine being the most abundant in eukaryotic membranes. CHKA with its paralog (CHKB) phosphorylates either choline or ethanolamine to phosphocholine or phosphoethanolamine respectively with conversion of ATP to ADP. As the authors comment, biallelic pathogenic variants in CHKB cause a NDD with muscular dystrophy, hypotonia, ID, microcephaly and structural mitochondrial anomalies (MIM 602541). [Prominent mitochondrial patterning was observed in a single muscle biopsy available from an individual with biallelic CHKA variants]. Other disorders of the Kennedy pathway (due to biallelic PCYT2, SELENOI, PCYT1A variants) present with overlapping features incl. variable DD/ID (no-severe), microcephaly, seizures, visual impairment etc. CHKA variants were either absent or observed once in gnomAD, affected highly conserved AAs with multiple in silico predictions in favor of a deleterious effect. In silico modeling suggests structural effects for several of the missense variants (Arg141Trp, Pro194Ser presumably affect ADP binding, Phe341 lying close to the binding site of phosphocholine). Each of the missense variants was expressed in yeast cells and W. Blot suggested expression at the expected molecular weight at comparative levels. The 3 aforementioned variants exhibited reduced catalytic activity (20%, 15%, 50% respectively). NMD is thought to underly the deleterious effect of the frameshift one (not studied). The start-loss variant is expected to result in significantly impaired expression and protein function as eventual utilization of the next possible start codon - occurring at position 123 - would remove 26% of the protein. Chka(-/-) is embryonically lethal in mice, suggesting that complete loss is not compatible with life. Reduction of choline kinase activity by 30% in heterozygous mice did not appear to result in behavioral abnormalities although this was not studied in detail (PMID cited: 18029352). Finally, screening of 1566 mouse lines identified 198 genes whose disruption yields neuroanatomical phenotypes, Chka(+/-) mice being among these (PMID cited: 31371714). There is no associated phenotype in OMIM, Gene2Phenotype or SysID. Overall this gene can be considered for inclusion in the ID and epilepsy panes with green or amber rating (>3 individuals, >3 variants, variant studies, overlapping phenotype of disorders belonging to the same pathway, etc). Consider also inclusion in the microcephaly panel (where available this seemed to be of postnatal onset). Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4370 | KCND2 |
Zornitza Stark gene: KCND2 was added gene: KCND2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: KCND2 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: KCND2 were set to 24501278; 16934482; 29581270; 34245260 Phenotypes for gene: KCND2 were set to Neurodevelopmental disorder MONDO:0700092; global developmental delay, HP:0001263; seizure, HP:0001250 Review for gene: KCND2 was set to GREEN Added comment: 6 new unrelated cases with developmental delay reported in PMID: 34245260 (Zhang et al 2021), 3 of whom had seizures. All had heterozygous missense variants of KCND2 in sites known to be critical for channel gating (E323K, P403A, two individuals, V404L, two individuals and V404M). Functional studies suggest that these missense changes cause both a partial loss-of-function (LOF) and gain-of-function (GOF). The V404 change appears to increase epileptic seizure susceptibility with the 3 patients with a V404 change showing this phenotype. PMID:24501278 - Lee et al, 2014 - reports pair of monozygotic twin boys with infantile onset severe refractory epilepsy and autism. A de novo heterozygous missense variant was identified by WES - V404M. PMID: 29581270 - Lin et al, 2018 - performed functional work that shows V404M enhances inactivation of channels that have not yet opened and dramatically impairs the inactivation of channels that have opened. PMID:16934482 - Singh et al, 2006 - reports a patient with cognative impairment who also went on to have seizures starting from age 13 with a 5 bp deletion in KCND2 leading to premature stop codon. The proband's asymptomatic father also shared this variant. Sources: Literature Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4343 | SNIP1 | Zornitza Stark edited their review of gene: SNIP1: Added comment: A single (founder) variant NM_024700.4:c.1097A>G, p.(Glu366Gly) has been reported in over 30 cases of Psychomotor retardation, epilepsy, and craniofacial dysmorphism OMIM:614501 in the Amish community (PMIDs: 22279524; 34570759). Cases are homozygous for this variant and unaffected members of the families are heterozygous or wt. Overexpression of the equivalent mouse variant in mouse inner medullary collecting duct cells, resulted in a more aggregated appearance in the nucleus compared to wildtype. The variant protein maybe unstable as Western blots showed reduced levels of the variant protein (PMID: 22279524). Whole transcriptomic analysis of patient blood was performed in PMID: 34570759. This revealed 11 upregulated and 32 downregulated genes, of which 24 had previously been associated with neurological disease.; Changed rating: AMBER | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4086 | LSM11 | Zornitza Stark Phenotypes for gene: LSM11 were changed from type I interferonopathy Aicardi–Goutières syndrome to Aicardi-Goutieres syndrome 8, MIM# 619486 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4058 | ARF3 |
Konstantinos Varvagiannis gene: ARF3 was added gene: ARF3 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ARF3 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: ARF3 were set to 34346499 Phenotypes for gene: ARF3 were set to Global developmental delay; Intellectual disability; Seizures; Morphological abnormality of the central nervous system Penetrance for gene: ARF3 were set to unknown Added comment: Sakamoto et al (2021 - PMID: 34346499) provide some evidence that monoallelic ARF3 pathogenic variants may be associated with a NDD with brain abnormality. Using trio exome sequencing, the authors identified 2 individuals with NDD harboring de novo ARF3 variants, namely: NM_001659.2:c.200A>T / p.Asp67Val and c.296G>T / p.Arg99Leu. Individual 1 (with Asp67Val / age : 4y10m), appeared to be more severelely affected with prenatal onset progressive microcephaly, severe global DD, epilepsy. Upon MRI there was cerebellar and brainstem atrophy. Individual 2 (Arg99Leu / 14y) had severe DD and ID (IQ of 23), epilepsy and upon MRI cerebellar hypoplasia. This subject did not exhibit microcephaly. Common facial features incl. broad nose, full cheeks, small philtrum, strabismus, thin upper lips and abnormal jaw. There was no evidence of systemic involvement in both. ARF3 encodes ADP-ribosylation factor 3. Adenosine diphosphate ribosylation factors (ARFs) are key proteins for regulation of cargo sorting at the Golgi network, with ARF3 mainly working at the trans-Golgi network. ARFs belong to the small GTP-binding protein (G protein) superfamily. ARF3 switches between an active GTP-bound form and an inactive GDP-bound form, regulated by guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs) respectively. Members of the ARF superfamily regulate various aspects of membrane traffic, among others in neurons. There are 5 homologs of ARF families, divided in 3 classes. ARF3 and ARF1 belong to class I. Monoallelic ARF1 mutations are associated with Periventricular nodular heterotopia 8 (MIM 618185). In vivo, in vitro and in silico studies for the 2 variants suggest that both impair the Golgi transport system although each variant most likely exerts a different effect (gain-of-function for Arg99Leu vs loss-of-function/dominant-negative for Asp67Val). This was also reflected in somewhat different phenotype of the subjects with the respective variants. Common features included severe DD, epilepsy and brain abnormalities although Asp67Val was associated with diffuse brain atrophy as well as congenital microcephaly and Arg99Leu with cerebellar hypoplasia. Evidence to support the effect of each variant include: Arg99Leu: Had identical Golgi localization to that of wt Had increased binding activity with GGA1, a protein recruited by the GTP-bound active form of ARF3 to the TGN membrane (supporting GoF) In silico structural analysis suggested it may fail to stabilize the conformation of Asp26, resulting in impaired GTP hydrolysis (GoF). In transgenic fruit flies, evaluation of the ARF3 variant toxicity using the rough eye phenotype this variant was associated with increased severity of the r-e phenotype similar to a previously studied GoF variant (Gln71Leu) Asp67Val: Did not show a Golgi-like pattern of localization (similar to Thr31Asn a previously studied dominant-negative variant) Displayed decreased protein stability In silico structural analysis suggested that Asp67Val may lead to compromised binding of GTP or GDP (suggestive of LoF) In transgenic Drosophila eye-specific expression of Asp67Val (similar to Thr31Asn, a known dominant-negative variant) was lethal possibly due to high toxicity in very small amounts in tissues outside the eye. There is no associated phenotype in OMIM, G2P or SysID. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4053 | PLXNA2 |
Konstantinos Varvagiannis gene: PLXNA2 was added gene: PLXNA2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature,Other Mode of inheritance for gene: PLXNA2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PLXNA2 were set to 34327814 Phenotypes for gene: PLXNA2 were set to Intellectual disability; Abnormality of the face; Failure to thrive; Abnormal heart morphology Penetrance for gene: PLXNA2 were set to Incomplete Review for gene: PLXNA2 was set to AMBER Added comment: Altuame et al (2021 - PMID: 34327814) describe 3 individuals from 2 consanguineous Arab families with biallelic PLXNA2 variants. The index patient from the 1st family presented with CHD (hypoplastic right ventricle, ASD), DD and moderate ID (IQ of 40), failure to thrive as well as some dysmorphic features (obtuse mandibular angle, mild overbite, synophrys with downslanting p-f, strabismus, etc). There were additional features (eg. postaxial polydactyly) which were found in other affected and unaffected family members. Exome sequencing with autozygome analysis revealed homozygosity for a PLXNA2 stopgain variant (NM_025179:c.3603C>A / p.(Cys1201*)). Sanger confirmation was carried out and segregation analyses confirmed carrier status of the unaffected parents and a sib as well as a brother homozygous for the same variant. Clinical evaluation of the latter, following this finding revealed borderline intellectual functioning, ADHD, failure to thrive. There was no mandibular anomaly or overbite and no clinical evidence of CHD (no echo performed). The index patient from the 2nd consanguineous family was evaluated for ID (IQ of 63), with previous borderline motor development, ADHD and some dysmorphic features (obtuse mandibular angle and overbite). There was no clinical evidence of CHD (no echo performed). Exome sequencing with autozygosity mapping revealed a homozygous missense PLXNA2 variant (c.3073G>A / p.(Asp1025Asn), present only once in gnomAD (htz), with rather non-concordant in silico predictions SIFT 0.22, PolyPhen 0.682 and CADD 23.5. The aa was however highly conserved. Segregation analysis confirmed carrier state of the parents and 2 unaffected sibs, with a 3rd sib homozygous for the wt allele. As the authors discuss: *PLXNA2 belongs to the plexin family of genes, encoding transmbembrane proteins functioning as semaphorin receptors. It has predominant expression in neural tissue. The protein is thought to bind semaphorin-3A, -3C or -5 followed by plexin A2 dimerization, activation of its GTPase-activating protein domain, negative regulation of Rap1B GTPase and initiation of a signal transduction cascade mediating axonal repulsion/guidance, dendritic guidance, neuronal migration. *Murine Plxna2 knockout models display structural brain defects. In addition they display congenital heart defects incl. persistent truncus arteriosus and interrupted aortic arch. *Rare CNVs in adult humans with tetralogy of Fallot have suggested a potential role of PLXNA2 in cardiac development and CHD. *Expression and the role of PLXNA2 in human chondrocytes as well as a GWAS in 240 japanese patients with mandibular prognathism where PLXNA2 was suggested as a susceptibility locus. Overall, the authors recognize some common features (as for cognitive functioning, some dysmorphic features incl. obtuse mandibular angle and overbite in 2 unrelated subjects, failure to thrive 3/3) and provide plausible explanations for the variability / discordance of others eg: - Cyanotic heart disease explaining discordance in cognitive outcome among sibs - Incomplete penetrance for CHD (and/or ID or mandibular anomaly) as for few AR disorders and/or - Additional pathogenic variants possibly explaining the CHD in the first subject. There is no associated phenotype in OMIM or G2P. SysID includes PLXNA2 among the candidate ID genes. Sources: Literature, Other |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4051 | VPS50 |
Konstantinos Varvagiannis gene: VPS50 was added gene: VPS50 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: VPS50 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: VPS50 were set to 34037727 Phenotypes for gene: VPS50 were set to Neonatal cholestatic liver disease; Failure to thrive; Profound global developmental delay; Postnatal microcephaly; Seizures; Abnormality of the corpus callosum Penetrance for gene: VPS50 were set to Complete Review for gene: VPS50 was set to AMBER Added comment: Schneeberger et al (2021 - PMID: 34037727) describe the phenotype of 2 unrelated individuals with biallelic VPS50 variants. Common features included transient neonatal cholestasis, failure to thrive, severe DD with failure to achieve milestones (last examination at 2y and 2y2m respectively), postnatal microcephaly, seizures (onset at 6m and 25m) and irritability. There was corpus callosum hypoplasia on brain imaging. Both individuals were homozygous for variants private to each family (no/not known consanguinity applying to each case). The first individual was homozygous for a splicing variant (NM_017667.4:c.1978-1G>T) and had a similarly unaffected sister deceased with no available DNA for testing. The other individual was homozygous for an in-frame deletion (c.1823_1825delCAA / p.(Thr608del)). VPS50 encodes a critical component of the endosome-associated recycling protein (EARP) complex, which functions in recycling endocytic vesicles back to the plasma membrane [OMIM based on Schindler et al]. The complex contains VPS50, VPS51, VPS52, VPS53, the three latter also being components of GARP (Golgi-associated-retrograde protein) complex. GARP contains VPS54 instead of VPS50 and is required for trafficking of proteins to the trans-golgi network. Thus VPS50 (also named syndetin) and VPS54 function in the EARP and GARP complexes, to define directional movement of their endocytic vesicles [OMIM based on Schindler et al]. The VPS50 subunit is required for recycling of the transferrin receptor. As discussed by Schneeberger et al (refs provided in text): - VPS50 has a high expression in mouse and human brain as well as throughout mouse brain development. - Mice deficient for Vps50 have not been reported. vps50 knockdown in zebrafish results in severe developmental defects of the body axis. Knockout mice for other proteins of the EARP/GARP complex (e.g. Vps52, 53 and 54) display embryonic lethality. Studies performed by Schneeberger et al included: - Transcript analysis for the 1st variant demonstrated skipping of ex21 (in patient derived fabriblasts) leading to an in frame deletion of 81 bp (r.1978_2058del) with predicted loss of 27 residues (p.Leu660_Leu686del). - Similar VPS50 mRNA levels but significant reduction of protein levels (~5% and ~8% of controls) were observed in fibroblasts from patients 1 and 2. Additionally, significant reductions in the amounts of VPS52 and VPS53 protein levels were observed despite mRNA levels similar to controls. Overall, this suggested drastic reduction of functional EARP complex levels. - Lysosomes appeared to have similar morphology, cellular distribution and likely unaffected function in patient fibroblasts. - Transferrin receptor recycling was shown to be delayed in patient fibroblasts suggestive of compromise of endocytic-recycling function. As the authors comment, the phenotype of both individuals with biallelic VPS50 variants overlaps with the corresponding phenotype reported in 15 subjects with biallelic VPS53 or VPS51 mutations notably, severe DD/ID, microcephaly and early onset epilepsy, CC anomalies. Overall, for this group, they propose the term "GARP and/or EARP deficiency disorders". There is no VPS50-associated phenotype in OMIM or G2P. SysID includes VPS50 among the ID candidate genes. Consider inclusion in other relevant gene panels (e.g. for neonatal cholestasis, epilepsy, microcephaly, growth failure in early infancy, corpus callosum anomalies, etc) with amber rating pending further reports. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4033 | UBR1 | Zornitza Stark changed review comment from: >50 unrelated families reported, reviewed in PMID: 24599544. Common clinical features include poor growth, mental retardation, and variable dysmorphic features, including aplasia or hypoplasia of the nasal alae, abnormal hair patterns or scalp defects, and oligodontia. Other features include hypothyroidism, sensorineural hearing loss, imperforate anus, and pancreatic exocrine insufficiency.; to: >50 unrelated families reported, reviewed in PMID: 24599544. Common clinical features include poor growth, intellectual disability, and variable dysmorphic features, including aplasia or hypoplasia of the nasal alae, abnormal hair patterns or scalp defects, and oligodontia. Other features include hypothyroidism, sensorineural hearing loss, imperforate anus, and pancreatic exocrine insufficiency. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4020 | CLCN3 |
Zornitza Stark gene: CLCN3 was added gene: CLCN3 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: CLCN3 was set to BOTH monoallelic and biallelic (but BIALLELIC mutations cause a more SEVERE disease form), autosomal or pseudoautosomal Publications for gene: CLCN3 were set to 34186028 Phenotypes for gene: CLCN3 were set to Neurodevelopmental disorder Mode of pathogenicity for gene: CLCN3 was set to Other Review for gene: CLCN3 was set to GREEN Added comment: 11 individuals reported, 9 that carried 8 different rare heterozygous missense variants in CLCN3, and 2 siblings that were homozygous for an NMD-predicted frameshift variant likely abolishing ClC-3 function. All missense variants were confirmed to be de novo in eight individuals for whom parental data was available. The 11 individuals in the cohort share clinical features of variable severity. All 11 have GDD or ID and dysmorphic features, and a majority has mood or behavioural disorders and structural brain abnormalities: - Structural brain abnormalities on MRI (9/11) included partial or full agenesis of the corpus callosum (6/9), disorganized cerebellar folia (4/9), delayed myelination (3/9), decreased white matter volume (3/9), pons hypoplasia (3/9), and dysmorphic dentate nuclei (3/9). Six of those with brain abnormalities also presented with seizures. - Nine have abnormal vision, including strabismus in four and inability to fix or follow in the two with homozygous loss-of-function variants. - Hypotonia ranging from mild to severe was reported in 7 of the 11 individuals. - Six have mood or behavioural disorders, particularly anxiety (3/6). - Consistent dysmorphic facial features included microcephaly, prominent forehead, hypertelorism, down-slanting palpebral fissures, full cheeks, and micrognathia. The severity of disease in the two siblings with homozygous disruption of ClC-3 is consistent with the drastic phenotype seen in Clcn3 KO mice. The disease was more severe in two siblings carrying homozygous loss-of-function variants with the presence of GDD, absent speech, seizures, and salt and pepper fundal pigmentation in both individuals, with one deceased at 14 months of age. The siblings also had significant neuroanatomical findings including diffusely decreased white matter volume, thin corpora callosa, small hippocampi, and disorganized cerebellar folia. Supporting biallelic inheritance for LoF variants, disruption of mouse Clcn3 results in drastic neurodegeneration with loss of the hippocampus a few months after birth and early retinal degeneration. Clcn3−/− mice display severe neurodegeneration, whereas heterozygous Clcn3+/− mice appear normal. Patch-clamp studies were used to investigate four of the missense variants. These suggested a gain of function in two variants with increased current in HEK cells, however they also showed reduced rectification of voltage and a loss of transient current, plus decreased current amplitude, glycosylation and surface expression when expressed in oocytes, and were suspected to interfere with channel gating and a negative feedback mechanism. These effects were also shown to vary depending on pH levels. The current of the remaining two variants did not differ from WT. For heterozygous missense variants, the disruption induced may be at least partially conferred to mutant/WT homodimers and mutant/ClC-4 heterodimers. Both loss and gain of function in this gene resulted in the same phenotype. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4002 | SYNCRIP |
Konstantinos Varvagiannis gene: SYNCRIP was added gene: SYNCRIP was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: SYNCRIP was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: SYNCRIP were set to 34157790; 30504930; 27479843; 23020937 Phenotypes for gene: SYNCRIP were set to Global developmental delay; Intellectual disability; Autism; Myoclonic atonic seizures; Abnormality of nervous system morphology Review for gene: SYNCRIP was set to AMBER Added comment: Semino et al (2021 - PMID: 34157790) provide clinical details on 3 unrelated individuals with de novo SYNCRIP variants and provide a review of 5 additional subjects previously identified within large cohorts in the literature and databases. Features included DD, ID (7/7 for whom this information was available), ASD or autistic features (4/7). MRI abnormalities were observed in 3 (widening of CSF spaces, periventricular nodular heterotopia, prominent lat. ventricles). Epilepsy (myoclonic-astatic epilepsy / Doose syndrome) was reported for 2(/8) individuals. The 3 patients here reported were identified following trio/singleton exome with Sanger confirmation of the variants and their de novo occurrence. Variants are in almost all cases de novo (7/7 for whom this was known) and in 5/8 cases were pLoF, in 2/8 missense SNVs while a case from DECIPHER had a 77.92 kb whole gene deletion not involving other genes with unknown inheritance. Overall the variants reported to date include [NM_006372.5]: 1 - c.858_859del p.(Gly287Leufs*5) 2 - c.854dupA p.(Asn285Lysfs*8) 3 - c.734T>C p.(Leu245Pro) 4 - chr6:85605276-85683190 deletion (GRCh38) 5 - c.629T>C p.(Phe210Ser) 6 - c.1573_1574delinsTT p.(Gln525Leu) 7 - c.1247_1250del p.(Arg416Lysfs*145) 8 - c.1518_1519insC p.(Ala507Argfs*14) [P1-3: this report, P4: DECIPHER 254774, P5-6: Guo et al 2019 - PMID: 30504930, P7: Lelieveld et al 2016 - PMID: 27479843, P8: Rauch et al 2012 - PMID: 23020937 / all other Refs not here reviewed, clinical details summarized by Semino et al in table 1] SYNCRIP (also known as HNRNPQ) encodes synaptotagmin‐binding cytoplasmic RNA‐interacting protein. As the authors note, this RNA-binding protein is involved in multiple pathways associated with neuronal/muscular developmental disorders. Several references are provided for its involvement in regulation of RNA metabolism, among others sequence recognition, pre-mRNA splicing, translation, transport and degradation. Mutations in other RNA-interacting proteins and hnRNP members (e.g. HNRNPU, HNRNPD) are associated with NDD. The missense variant (p.Leu245Pro) is within RRM2 one of the 3 RNA recognition motif (RRM) domains of the protein. These 3 domains, corresponding to the central part of the protein (aa 150-400), are relatively intolerant to variation (based on in silico predictions and/or variation in gnomAD). Leu245 localizes within an RNA binding pocket and in silico modeling suggests alteration of the tertiary structure and RNA-binding capacity of RRM2. There are no additional studies performed. Overall haploinsufficiency appears to be the underlying disease mechanism based on the truncating variants and the gene deletion. [pLI in gnomAD : 1, %HI : 2.48%] Animal models are not discussed. There is no associated phenotype in OMIM. This gene is included in the DD panel of G2P (monoallelic LoF variants / SYNCRIP-related developmental disorder). SysID also lists SYNCRIP within the current primary ID genes. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4001 | CAMK4 |
Konstantinos Varvagiannis gene: CAMK4 was added gene: CAMK4 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature,Other Mode of inheritance for gene: CAMK4 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: CAMK4 were set to 30262571; 33098801; 33211350 Phenotypes for gene: CAMK4 were set to Global developmental delay; Intellectual disability; Autism; Behavioral abnormality; Abnormality of movement; Dystonia; Ataxia; Chorea; Myoclonus Penetrance for gene: CAMK4 were set to Complete Review for gene: CAMK4 was set to GREEN Added comment: 3 publications by Zech et al (2018, 2020 - PMIDs : 30262571, 33098801, 33211350) provide clinical details on 3 individuals, each harboring a private de novo CAMK4 variant. Overlapping features included DD, ID, behavoral issues, autism and abnormal hyperkinetic movements. Dystonia and chorea in all 3 appeared 3-20 years after initial symptoms. CAMK4 encodes Calcium/Calmodulin-dependent protein kinase IV, an important mediator of calcium-mediated activity and dynamics, particularly in the brain. It is involved in neuronal transmission, synaptic plasticity, and neuronal gene expression required for brain development and neuronal homeostasis (summary by OMIM based on Zech et al, 2018). The 473 aa enzyme has a protein kinase domain (aa 46-300) and a C-terminal autoregulatory domain (aa 305-341) the latter comprising an autoinhibitory domain (AID / aa 305-321) and a calmodulin-binding domain (CBD / aa 322-341) [NP_001735.1 / NM_001744.4 - also used below]. Variants in all 3 subjects were identified following trio-WES and were in all cases protein-truncating, mapping to exon 10 or exon 10-intron 10 junction, expected to escape NMD and cause selective abrogation of the autoinhibitory domain (aa 305-321) leading overall to gain-of-function. Variation databases include pLoF CAMK4 variants albeit in all cases usptream or downstream of this region (pLI of this gene in gnomAD: 0.51). Variants leading to selective abrogation of the autoregulatory domain have not been reported. Extensive evidence for the GoF effect of the variant has been provided in the first publication. Several previous studies have demonstrated that abrogation of the AID domain leads to consitutive activation (details below). Mouse models - though corresponding to homozygous loss of function - support a role for CAMKIV in cognitive and motor symptoms. Null mice display tremulous and ataxic movements, deficiencies in balance and sensorimotor performance associated with reduced number of Purkinje neurons (Ribar et al 2000, PMID: 11069976 - not reviewed). Wei et al (2002, PMID: 12006982 - not reviewed) provided evidence for alteration in hippocampal physiology and memory function. Heterozygous mutations in other genes for calcium/calmodulin-dependent protein kinases (CAMKs) e.g. CAMK2A/CAMK2B (encoding subunits of CAMKII) have been reported in individuals with ID. --- The proband in the first publication (PMID: 30262571) was a male with DD, ID, behavioral difficulties (ASD, autoaggression, stereotypies) and hyperkinetic movement disorder (myoclonus, chorea, ataxia) with severe generalized dystonia (onset at the age of 13y). Brain MRI demonstrated cerebellar atrophy. Extensive work-up incl. karyotyping, CMA, DYT-TOR1A, THAP1, GCH1, SCA1/2/3/6/7/8/12/17, Friedreich's ataxia and FMR1 analysis was negative.F Trio WES identified a dn splice site variant (c.981+1G>A) in the last exon-intron junction. RT-PCR followed by gel electrophoresis and Sanger in fibroblasts from an affected and control subject revealed that the proband had - as predicted by the type/location of the variant - in equal amount 2 cDNA products, a normal as well as a truncated one. Sequencing of the shortest revealed utilization of a cryptic donor splice site upstream of the mutated donor leading to a 77bp out-of-frame deletion and introduction of a premature stop codon in the last codon (p.Lys303Serfs*28). Western blot in fibroblast cell lines revealed 2 bands corresponding to the normal protein product as well as to the p.Lys303Serfs*28 although expression of the latter was lower than that of the full length protein. Several previous studies have shown that mutant CAMKIV species that lack the autoinhibitory domain are consitutively active (several Refs provided). Among others Chatila et al (1996, PMID: 8702940) studied an in vitro-engineered truncation mutant (Δ1-317 - truncation at position 317 of the protein) with functionally validated gain-of-function effect. To prove enhanced activity of the splicing variant, Zech et al assessed phosphorylation of CREB (cyclic AMP-responsive element binding protein), a downstream substrate of CAMKIV. Immunobloting revealed significant increase of CREB phosphorylation in patient fibroblasts compared to controls. Overactivation of CAMKIV signaling was reversed when cells were treated with STO-609 an inhibitor of CAMKK, the ustream activator of CAMKIV. Overall the authors demonstrated that loss of CAMKIV autoregulatory domain due to this splice variant had a gain-of-function effect. ---- Following trio-WES, Zech et al (2020 - PMID: 33098801) identified another relevant subject within cohort of 764 individuals with dystonia. This 12-y.o. male, harboring a different variant affecting the same donor site (c.981+1G>T), presented DD, ID, dystonia (onset at 3y) and additional movement disorders (myoclonus, ataxia) as well as similar behavior (ASD, autoaggression, stereotypies). [Details in suppl. p20]. ---- Finally Zech et al (2020 - PMID: 33211350) reported on a 24-y.o. woman with adolescence onset choreodystonia. Other features included DD, moderate ID, absence seizures in infancy, OCD with anxiety and later diagnosis of ASD. Trio WES revealed a dn stopgain variant (c.940C>T; p.Gln314*). ---- There is no associated phenotype in OMIM, G2P. In SysID CAMK4 is listed among the current primary ID genes. ---- Please consider inclusion in other relevant panels. Sources: Literature, Other |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3967 | RING1 |
Zornitza Stark gene: RING1 was added gene: RING1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: RING1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: RING1 were set to 29386386 Phenotypes for gene: RING1 were set to microcephaly; intellectual disability Review for gene: RING1 was set to RED Added comment: Not associated with any phenotype in OMIM. PMID: 29386386 - Pierce et al 2018 - report a 13 yo female with a de novo RING1 p.R95Q variant and syndromic neurodevelopmental disabilities. Early motor and language development were normal but were delayed after the first year of life. Cognitive testing showed a verbal IQ of 55 and a visual performance IQ of 63. Head circumference at birth was -4.9 SD, and -4.2 SD at age 13 which falls into the severe microcephaly category. C. elegans with either the missense mutation or complete knockout of spat-3 (the suggested RING1 ortholog) were defective in monoubiquitylation of histone H2A and had defects in neuronal migration and axon guidance. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3951 | JPH3 |
Seb Lunke gene: JPH3 was added gene: JPH3 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: JPH3 was set to Unknown Publications for gene: JPH3 were set to 33824468 Phenotypes for gene: JPH3 were set to Intellectual disability; dystonia Review for gene: JPH3 was set to RED Added comment: One homozygous truncating variant (NM_020655.4: c.1740dup; p.(Val581Argfs*137)) found in a female individual affected with genetically undetermined neurodevelopmental anomalies (including delayed motor milestones, abnormal social communication, language difficulties and borderline cognitive impairment) and paroxysmal attacks of dystonia since her early infancy. No functional work were performed. Only STRs disease causing, see separate STR list. No evidence for SNVs etc. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3882 | SLC13A5 | Zornitza Stark Phenotypes for gene: SLC13A5 were changed from to Developmental and epileptic encephalopathy 25, with amelogenesis imperfecta MIM#615905; MONDO:0014392 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3879 | SLC13A5 | Zornitza Stark reviewed gene: SLC13A5: Rating: GREEN; Mode of pathogenicity: None; Publications: 24995870, 26384929; Phenotypes: Developmental and epileptic encephalopathy 25, with amelogenesis imperfecta MIM#615905, MONDO:0014392; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3538 | SATB1 |
Zornitza Stark edited their review of gene: SATB1: Added comment: Kohlschutter-Tonz syndrome-like (KTZSL) is characterized by global developmental delay with moderately to severely impaired intellectual development, poor or absent speech, and delayed motor skills. Although the severity of the disorder varies, many patients are nonverbal and have hypotonia with inability to sit or walk. Early-onset epilepsy is common and may be refractory to treatment, leading to epileptic encephalopathy and further interruption of developmental progress. Most patients have feeding difficulties with poor overall growth and dysmorphic facial features, as well as significant dental anomalies resembling amelogenesis imperfecta. This phenotype was reported in 28 patients (patients 13 to 40, PMID 33513338), including 9 patients from 3 families. Most variants were de novo, though some were inherited, suggestive of incomplete penetrance and variable expressivity. Developmental delay with dysmorphic facies and dental anomalies (DEFDA) is characterized by generally mild global developmental delay with variably impaired intellectual development, walking by 2 to 3 years, and slow language acquisition. The severity of the disorder ranges from moderate cognitive deficits to mild learning difficulties or behavioral abnormalities. Most patients have dysmorphic facial features, often with abnormal dentition and nonspecific visual defects, such as myopia, astigmatism, and strabismus. Although rare, involvement of other systems, such as skeletal, cardiac, and gastrointestinal, may be present. 12 individuals from 11 families reported (one inherited variant, affected parent).; Changed phenotypes: Kohlschutter-Tonz syndrome-like, MIM# 619229, Developmental delay with dysmorphic facies and dental anomalies, MIM# 619228, Developmental disorders |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3368 | LSM11 |
Ee Ming Wong gene: LSM11 was added gene: LSM11 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: LSM11 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: LSM11 were set to PMID: 33230297 Phenotypes for gene: LSM11 were set to type I interferonopathy Aicardi–Goutières syndrome Review for gene: LSM11 was set to RED gene: LSM11 was marked as current diagnostic Added comment: - Two affected siblings from a consanguineous family carrying a homozygous variant in LSM11 - Compared to control fibroblasts, patient fibroblasts were enriched for misprocessed forms of replication-dependent histone (RDH) mRNAs - Knockdown of LSM11 in THP-1 cells results in an increase in misprocessed RDH mRNA and interferon signaling (added as Red as per discussion with Seb) Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3264 | RAP1B |
Chirag Patel gene: RAP1B was added gene: RAP1B was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: RAP1B was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: RAP1B were set to PMID: 32627184 Phenotypes for gene: RAP1B were set to RAP1B‐associated phenotype, no OMIM # Review for gene: RAP1B was set to RED Added comment: De novo variants in the RAP1B gene (c.35G>T p.(Gly12Val) and c.178G>C p.(Gly60Arg)) in two unrelated patients with thrombocytopenia, microcephaly, learning difficulties, renal malformations, structural anomalies of the brain and other features (not Kabuki like). RAP1B is a member of the RAS superfamily of small GTPases. There is strong evidence that the p.Gly12Val and p.Gly60Arg variants in the RAP1B gene lead into a dysregulation of the downstream pathway. Both substitutions have been described previously as dominant constitutively active in RAS‐related proteins (gain of function variants). Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3102 | PRKACB |
Konstantinos Varvagiannis gene: PRKACB was added gene: PRKACB was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: PRKACB was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: PRKACB were set to 33058759 Phenotypes for gene: PRKACB were set to Postaxial hand polydactyly; Postaxial foot polydactyly; Common atrium; Atrioventricular canal defect; Narrow chest; Abnormality of the teeth; Intellectual disability Penetrance for gene: PRKACB were set to Complete Review for gene: PRKACB was set to AMBER Added comment: ID was a feature in 2/4 individuals with PRKACB pathogenic variant reported to date. ------ Palencia-Campos et al (2020 - PMID: 33058759) report on the phenotype of 3 individuals heterozygous for PRKACA and 4 individuals heterozygous for PRKACB pathogenic variants. The most characteristic features in all individuals with PRKACA/PRKACB mutation, included postaxial polydactyly of hands (6/7 bilateral, 1/7 unilateral) and feet (4/7 bilateral, 1/7 unilateral), brachydactyly and congenital heart defects (CHD 5/7) namely a common atrium or AVSD. Two individuals with PRKACA variant who did not have CHD had offspring with the same variant and an AVSD. Other variably occurring features included short stature, limbs, narrow chest, abnormal teeth, oral frenula, nail dysplasia. One individual with PRKACB variant presented tumors. Intellectual disability was reported in 2/4 individuals with PRKACB variant (1/4: mild, 1/4: severe). The 3 individuals with PRKACA variant did not present ID. As the phenotype was overall suggestive of Ellis-van Creveld syndrome (or the allelic Weyers acrofacial dysostosis), although these diagnoses were ruled out following analysis of EVC and EVC2 genes. WES was carried out in all. PRKACA : A single heterozygous missense variant was identified in 3 individuals from 3 families (NM_002730.4:c.409G>A / p.Gly137Arg) with 1 of the probands harboring the variant in mosaic state (28% of reads) and having 2 similarly affected offspring. The variant was de novo in one individual and inherited in a third one having a similarly affected fetus (narrow thorax, postaxial polyd, AVSD). PRKACB : 4 different variants were identified (NM_002731.3: p.His88Arg/Asn, p.Gly235Arg, c.161C>T - p.Ser54Leu). One of the individuals was mosaic for the latter variant, while in all other cases the variant had occurred de novo. Protein kinase A (PKA) is a tetrameric holoenzyme formed by the association of 2 catalytic (C) subunits with a regulatory (R) subunit dimer. Activation of PKA is achieved through binding of 2 cAMP molecules to each R-subunit, and unleashing(/dissociation) of C-subunits to engage substrates. PRKACA/B genes encode the Cα- and Cβ-subunits while the 4 functionally non-redundant regulatory subunits are encoded by PRKAR1A/1B/2A/2B genes. The authors provide evidence that the variants confer increased sensitivity of PKA holoenzymes to activation by cAMP (compared to wt). By performing ectopic expression of wt or mt PRKACA/B (variants studied : PRKACA p.Gly137Arg / PRKACB p.Gly235Arg) in NIH 3T3 fibroblasts, the authors demonstrate that inhibition of hedgehog signaling likely underlyies the developmental defects observed in affected individuals. As for PRKACA, the authors cite another study where a 31-month old female with EvC syndrome diagnosis was found to harbor the aforementioned variant (NM_001304349.1:c.637G>A:p.Gly213Arg corresponding to NM_002730.4:c.409G>A / p.Gly137Arg) as a de novo event. Without additional evidence at the time, the variant was considered to be a candidate for this subject's phenotype (Monies et al 2019 – PMID: 31130284). Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3078 | CSNK1G1 |
Konstantinos Varvagiannis changed review comment from: Gold et al (2020 - PMID: 33009664) report 5 individuals with CSNK1G1 variants, including updated information on a previously reported subject (Martin et al 2014 - PMID: 24463883). Features included DD (5/5) with associated expressive language delay, ASD (in at least 3/5), seizures (2/5), dysmorphic facial features (4/5 arched eyebrows, 3/5 prominent central incisors, 2/5 epicanthus) and limb anomalies (2/5 - proximally placed thumb, 5th f. clinodactyly, asymmetric overgrowth - the other individual had tapering fingers). GI problems were observed in 4/5. Two individuals had macrocephaly and one had microcephaly. There was no formal developmental assessment although ID might be implied in at least 3 individuals (p1: 20y - single words/regression in walking following a seizure episode, p2: 8y - first words at 5y, assistance to feed, dress and bathe, ASD, p4: 13y - regression, assistance to feed and dress). CSNK1G1 encodes the gamma-1 isoform of casein kinase 1, a protein involved in growth and cell morphogenesis. The gene has ubiquitous expression, incl. brain. As commented, in brain it regulates phosphorylation of NMDA receptors, playing a role in synaptic transmission (4 articles cited). One individual had a 1.2 kb deletion spanning exon 3 of CSNK1G1 [chr15:64550952-64552120 - GRCh37]. Parental samples were unavailable for this individual. Four individuals were found to harbor de novo CSNK1G1 variants [NM_022048.3: c.688C>T - p.(Arg230Trp) dn | c.1255C>T - p.(Gln419*) dn | c.1214+5G>A dn with in silico predictions in favor of splice disruption | c.419C>T - p.(Thr140Met) dn]. Arg230Trp is however present once in gnomAD. The stopgain variant is located in the last exon and predicted to skip NMD. There were no variant studies performed. The Drosophila gish gene encodes a CK1γ homolog with preferential expression in the mushroom body. Heterozygous and homozygous mutants exhibit impairment in memory retention, more severe in homozygous flies. gish was also identified as a seizure modifier in a fly epilepsy model (heterozygous para mt flies). The authors also speculate that impaired transduction of LRP6 (and WNT signaling) might be implicated. Finally the authors discuss the phenotype of individuals in Decipher one of whom (327861) harbors a frameshift variant and presenting ID, epilepsy and progressive spasticity. [NB. Inheritance of this variant is not specified, while this individual has a further inherited SCN2A missense SNV]. Two further Decipher cases with microdeletions spanning CSNK1G1 (and additional variants) are also discussed. Overall, this gene can be considered for inclusion with probably amber rating. Sources: Literature; to: Gold et al (2020 - PMID: 33009664) report 5 individuals with CSNK1G1 variants, including updated information on a previously reported subject (Martin et al 2014 - PMID: 24463883). Features included DD (5/5) with associated expressive language delay, ASD (in at least 3/5), seizures (2/5), dysmorphic facial features (4/5 arched eyebrows, 3/5 prominent central incisors, 2/5 epicanthus) and limb anomalies (2/5 - proximally placed thumb, 5th f. clinodactyly, asymmetric overgrowth - the other individual had tapering fingers). GI problems were observed in 4/5. Two individuals had macrocephaly and one had microcephaly. There was no formal developmental assessment although ID might be implied in at least 3 individuals (p1: 20y - single words/regression in walking following a seizure episode, p2: 8y - first words at 5y, assistance to feed, dress and bathe, ASD, p4: 13y - regression, assistance to feed and dress). CSNK1G1 encodes the gamma-1 isoform of casein kinase 1, a protein involved in growth and cell morphogenesis. The gene has ubiquitous expression, incl. brain. As commented, in brain it regulates phosphorylation of NMDA receptors, playing a role in synaptic transmission (4 articles cited). One individual had a 1.2 kb deletion spanning exon 3 of CSNK1G1 [chr15:64550952-64552120 - GRCh37]. Parental samples were unavailable for this individual. Four individuals were found to harbor de novo CSNK1G1 variants [NM_022048.3: c.688C>T - p.(Arg230Trp) dn | c.1255C>T - p.(Gln419*) dn | c.1214+5G>A dn with in silico predictions in favor of splice disruption | c.419C>T - p.(Thr140Met) dn]. Arg230Trp is however present once in gnomAD. The stopgain variant is located in the last exon and predicted to skip NMD. There were no variant studies performed. The Drosophila gish gene encodes a CK1γ homolog with preferential expression in the mushroom body. Heterozygous and homozygous mutants exhibit impairment in memory retention, more severe in homozygous flies. gish was also identified as a seizure modifier in a fly epilepsy model (heterozygous para mt flies). The authors also speculate that impaired transduction of LRP6 (and WNT signaling) might be implicated. Finally the authors discuss the phenotype of individuals in Decipher one of whom (327861) harbors a frameshift variant and presented ID, epilepsy and progressive spasticity. [NB. Inheritance of this variant is not specified, while this individual has a further inherited SCN2A missense SNV]. Two further Decipher cases with microdeletions spanning CSNK1G1 (and additional variants) are also discussed. Overall, this gene can be considered for inclusion with probably amber rating. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3078 | CSNK1G1 |
Konstantinos Varvagiannis changed review comment from: Gold et al (2020 - PMID: 33009664) report 5 individuals with CSNK1G1 variants, including updated information on a previously reported subject (Martin et al 2014 - PMID: 24463883). Features included DD (5/5) with associated expressive language delay, ASD (in at least 3/5), seizures (2/5), dysmorphic facial features (4/5 arched eyebrows, 3/5 prominent central incisors, 2/5 epicanthus) and limb anomalies (2/5 - proximally placed thumb, 5th f. clinodactyly, asymmetric overgrowth - the other individual had tapering fingers). GI problems were observed in 4/5. Two individuals had macrocephaly and one had microcephaly. There was no formal developmental assessment although ID might be implied in at least 3 individuals (p1: 20y - single words/regression in walking following a seizure episode, p2: 8y - first words at 5y, assistance to feed, dress and bathe, ASD, p4: 13y - regression, assistance to feed and dress). CSNK1G1 encodes the gamma-1 isoform of casein kinase 1, a protein involved in growth and cell morphogenesis. The gene has ubiquitous expression, incl. brain. As commented, in brain it regulates phosphorylation of NMDA receptors, playing a role in synaptic transmission (4 articles cited). One individual had a 1.2 kb deletion spanning exon 3 of CSNK1G1 [chr15:64550952-64552120 - GRCh37]. Parental samples were unavailable for this individual. Four individuals were found to harbor de novo CSNK1G1 variants [NM_022048.3: c.688C>T - p.(Arg230Trp) dn | c.1255C>T - p.(Gln419*) dn | c.1214+5G>A dn with in silico predictions in favor of splice disruption | c.419C>T - p.(Thr140Met) dn]. Arg230Trp is however present once in gnomAD. The stopgain variant is located in the last exon and predicted to skip NMD. There were no variant studies performed. The Drosophila gish gene encodes a CK1γ homolog with preferential expression in the mushroom body. Heterozygous and homozygous mutants exhibit impairment in memory retention, more severe in homozygous flies. gish was also identified as a seizure modifier in a fly epilepsy model (heterozygous para mt flies). The authors also speculate that impaired transduction of LRP6 (and WNT signaling) might be implicated. Finally the authors discuss the phenotype of individuals in Decipher one of whom (327861) harbors a frameshift variant and presenting ID, epilepsy and progressive spasticity. [NB. Inheritance of this variant is not specified, while this individual has a further inherited SCN2A missense SNV]. Two further Decipher cases with microdeletions spanning CSNK1G1 (and additional variants) also discussed. Overall, this gene can be considered for inclusion with probably amber rating. Sources: Literature; to: Gold et al (2020 - PMID: 33009664) report 5 individuals with CSNK1G1 variants, including updated information on a previously reported subject (Martin et al 2014 - PMID: 24463883). Features included DD (5/5) with associated expressive language delay, ASD (in at least 3/5), seizures (2/5), dysmorphic facial features (4/5 arched eyebrows, 3/5 prominent central incisors, 2/5 epicanthus) and limb anomalies (2/5 - proximally placed thumb, 5th f. clinodactyly, asymmetric overgrowth - the other individual had tapering fingers). GI problems were observed in 4/5. Two individuals had macrocephaly and one had microcephaly. There was no formal developmental assessment although ID might be implied in at least 3 individuals (p1: 20y - single words/regression in walking following a seizure episode, p2: 8y - first words at 5y, assistance to feed, dress and bathe, ASD, p4: 13y - regression, assistance to feed and dress). CSNK1G1 encodes the gamma-1 isoform of casein kinase 1, a protein involved in growth and cell morphogenesis. The gene has ubiquitous expression, incl. brain. As commented, in brain it regulates phosphorylation of NMDA receptors, playing a role in synaptic transmission (4 articles cited). One individual had a 1.2 kb deletion spanning exon 3 of CSNK1G1 [chr15:64550952-64552120 - GRCh37]. Parental samples were unavailable for this individual. Four individuals were found to harbor de novo CSNK1G1 variants [NM_022048.3: c.688C>T - p.(Arg230Trp) dn | c.1255C>T - p.(Gln419*) dn | c.1214+5G>A dn with in silico predictions in favor of splice disruption | c.419C>T - p.(Thr140Met) dn]. Arg230Trp is however present once in gnomAD. The stopgain variant is located in the last exon and predicted to skip NMD. There were no variant studies performed. The Drosophila gish gene encodes a CK1γ homolog with preferential expression in the mushroom body. Heterozygous and homozygous mutants exhibit impairment in memory retention, more severe in homozygous flies. gish was also identified as a seizure modifier in a fly epilepsy model (heterozygous para mt flies). The authors also speculate that impaired transduction of LRP6 (and WNT signaling) might be implicated. Finally the authors discuss the phenotype of individuals in Decipher one of whom (327861) harbors a frameshift variant and presenting ID, epilepsy and progressive spasticity. [NB. Inheritance of this variant is not specified, while this individual has a further inherited SCN2A missense SNV]. Two further Decipher cases with microdeletions spanning CSNK1G1 (and additional variants) are also discussed. Overall, this gene can be considered for inclusion with probably amber rating. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3078 | CSNK1G1 |
Konstantinos Varvagiannis gene: CSNK1G1 was added gene: CSNK1G1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: CSNK1G1 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: CSNK1G1 were set to 33009664 Phenotypes for gene: CSNK1G1 were set to Global developmental delay; Intellectual disability; Autism; Seizures; Abnormality of the face; Abnromality of limbs Penetrance for gene: CSNK1G1 were set to unknown Review for gene: CSNK1G1 was set to AMBER Added comment: Gold et al (2020 - PMID: 33009664) report 5 individuals with CSNK1G1 variants, including updated information on a previously reported subject (Martin et al 2014 - PMID: 24463883). Features included DD (5/5) with associated expressive language delay, ASD (in at least 3/5), seizures (2/5), dysmorphic facial features (4/5 arched eyebrows, 3/5 prominent central incisors, 2/5 epicanthus) and limb anomalies (2/5 - proximally placed thumb, 5th f. clinodactyly, asymmetric overgrowth - the other individual had tapering fingers). GI problems were observed in 4/5. Two individuals had macrocephaly and one had microcephaly. There was no formal developmental assessment although ID might be implied in at least 3 individuals (p1: 20y - single words/regression in walking following a seizure episode, p2: 8y - first words at 5y, assistance to feed, dress and bathe, ASD, p4: 13y - regression, assistance to feed and dress). CSNK1G1 encodes the gamma-1 isoform of casein kinase 1, a protein involved in growth and cell morphogenesis. The gene has ubiquitous expression, incl. brain. As commented, in brain it regulates phosphorylation of NMDA receptors, playing a role in synaptic transmission (4 articles cited). One individual had a 1.2 kb deletion spanning exon 3 of CSNK1G1 [chr15:64550952-64552120 - GRCh37]. Parental samples were unavailable for this individual. Four individuals were found to harbor de novo CSNK1G1 variants [NM_022048.3: c.688C>T - p.(Arg230Trp) dn | c.1255C>T - p.(Gln419*) dn | c.1214+5G>A dn with in silico predictions in favor of splice disruption | c.419C>T - p.(Thr140Met) dn]. Arg230Trp is however present once in gnomAD. The stopgain variant is located in the last exon and predicted to skip NMD. There were no variant studies performed. The Drosophila gish gene encodes a CK1γ homolog with preferential expression in the mushroom body. Heterozygous and homozygous mutants exhibit impairment in memory retention, more severe in homozygous flies. gish was also identified as a seizure modifier in a fly epilepsy model (heterozygous para mt flies). The authors also speculate that impaired transduction of LRP6 (and WNT signaling) might be implicated. Finally the authors discuss the phenotype of individuals in Decipher one of whom (327861) harbors a frameshift variant and presenting ID, epilepsy and progressive spasticity. [NB. Inheritance of this variant is not specified, while this individual has a further inherited SCN2A missense SNV]. Two further Decipher cases with microdeletions spanning CSNK1G1 (and additional variants) also discussed. Overall, this gene can be considered for inclusion with probably amber rating. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3062 | ITFG2 |
Konstantinos Varvagiannis gene: ITFG2 was added gene: ITFG2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ITFG2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: ITFG2 were set to 28397838; https://doi.org/10.1038/s41525-020-00150-z Phenotypes for gene: ITFG2 were set to Neurodevelopmental abnormality; Intellectual disability; Developmental regression; Ataxia Penetrance for gene: ITFG2 were set to Complete Review for gene: ITFG2 was set to AMBER Added comment: ITFG2 was suggested to be a candidate gene for autosomal recessive ID in the study by Harripaul et al (2018 - PMID: 28397838). The authors performed microarray and exome sequencing in 192 consanguineous families and identified a homozygous ITGF2 stopgain variant (NM_018463.3:c.472G>T / p.Glu158*) along with 3 additional variants segregating with ID within an investigated family (PK51). Cheema et al (2020 - https://doi.org/10.1038/s41525-020-00150-z) report briefly on a male, born to consanguineous parents presenting with NDD, seizures, regression and ataxia. There was a similarly affected female sibling. Evaluation of ROH revealed a homozygous ITFG2 nonsense variant [NM_018463.3:c.361C>T / p.(Gln121*)]. Families in this study were investigated by trio WES or WGS. Evaluation of data of the same lab revealed 3 additional unrelated subjects with overlapping phenotypes, notably NDD and ataxia. These individuals were - each - homozygous for pLoF variants [NM_018463.3:c.848-1G>A; NM_018463.3:c.704dupC, p.(Ala236fs), NM_018463.3:c.1000_1001delAT, p.(Ile334fs)]. As discussed in OMIM, ITFG2 encodes a subunit of the KICSTOR protein complex, having a role in regulating nutrient sensing by MTOR complex-1 (Wolfson et al 2017 - PMID : 28199306). Please consider inclusion in the ID panel with amber rating, pending further details. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3062 | SHMT2 |
Konstantinos Varvagiannis gene: SHMT2 was added gene: SHMT2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: SHMT2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: SHMT2 were set to 33015733 Phenotypes for gene: SHMT2 were set to Congenital microcephaly; Infantile axial hypotonia; Spastic paraparesis; Global developmental delay; Intellectual disability; Abnormality of the corpus callosum; Abnormal cortical gyration; Hypertrophic cardiomyopathy; Abnormality of the face; Proximal placement of thumb; 2-3 toe syndactyly Penetrance for gene: SHMT2 were set to Complete Review for gene: SHMT2 was set to GREEN Added comment: García‑Cazorla et al. (2020 - PMID: 33015733) report 5 individuals (from 4 families) with a novel brain and heart developmental syndrome caused by biallelic SHMT2 pathogenic variants. All affected subjects presented similar phenotype incl. microcephaly at birth (5/5 with OFC < -2 SD though in 2/5 cases N OFC was observed later), DD and ID (1/5 mild-moderate, 1/5 moderate, 3/5 severe), motor dysfunction in the form of spastic (5/5) paraparesis, ataxia/dysmetria (3/4), intention tremor (in 3/?) and/or peripheral neuropathy (2 sibs). They exhibited corpus callosum hypoplasia (5/5) and perisylvian microgyria-like pattern (4/5). Cardiac problems were reported in all, with hypertrophic cardiomyopathy in 4/5 (from 3 families) and atrial-SD in the 5th individual (1/5). Common dysmorphic features incl. long palpebral/fissures, eversion of lateral third of lower eylids, arched eyebrows, long eyelashes, thin upper lip, short Vth finger, fetal pads, mild 2-3 toe syndactyly, proximally placed thumbs. Biallelic variants were identified following exome sequencing in all (other investigations not mentioned). Identified variants were in all cases missense SNVs or in-frame del, which together with evidence from population databases and mouse model might suggest a hypomorphic effect of variants and intolerance/embryonic lethality for homozygous LoF ones. SHMT2 encodes the mitohondrial form of serine hydroxymethyltransferase. The enzyme transfers one-carbon units from serine to tetrahydrofolate (THF) and generates glycine and 5,10,methylene-THF. Mitochondrial defect was suggested by presence of ragged red fibers in myocardial biopsy of one patient. Quadriceps and myocardial biopsies of the same individual were overall suggestive of myopathic changes. While plasma metabolites were within N range and SHMT2 protein levels not significantly altered in patient fibroblasts, the authors provide evidence for impaired enzymatic function eg. presence of the SHMT2 substrate (THF) in patient but not control (mitochondria-enriched) fibroblasts , decrease in glycine/serine ratios, impared folate metabolism. Patient fibroblasts displayed impaired oxidative capacity (reduced ATP levels in a medium without glucose, diminished oxygen consumption rates). Mitochondrial membrane potential and ROS levels were also suggestive of redox malfunction. Shmt2 ko in mice was previously shown to be embryonically lethal attributed to severe mitochondrial respiration defects, although there was no observed brain metabolic defect. The authors performed Shmt2 knockdown in motoneurons in Drosophila, demonstrating neuromuscular junction (# of satellite boutons) and motility defects (climbing distance/velocity). Overall this gene can be considered for inclusion with (probably) green rating in gene panels for ID, metabolic / mitochondrial disorders, cardiomyopathy, congenital microcephaly, corpus callosum anomalies, etc. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3053 | NEMF |
Konstantinos Varvagiannis changed review comment from: Biallelic (and possibly monoallelic) pathogenic variants in this gene are associated with DD/ID. Martin et al (2020 - PMID:32934225) report on 8 individuals from 6 families with a juvenile neuromuscular disease due to biallelic NEMF variants. (In one of these 8 cases it could not be ruled out that a de novo and maternally inherited variant were on the same allele, as phase was not determined). A ninth individual with similar presentation was found to harbor a single NEMF missense SNV as de novo event (due to a speculated dominant-negative effect). This individual had a similar presentation. Features incl. hypotonia (4/8 with biallelic variant (B) | 1/1 monoallelic (M) ), DD/ID (7/8B | 0/1M) with speech delay as universal feature (8/8B | 1/1M), axonal neuropathy (3/3B | 1/1M), ataxia (3/8B | 0/1M). Other findings included tremor (1/7B | 1/1M), abnormal brain imaging (2/6B / ?/1M), kyphosis/scoliosis (4/8B | 0/1M), respiratory distress (1/8B | 0/1M). NEMF (Rqc2 in yeast) encodes the nuclear export mediator factor, a component of the Ribosome-associated Quality Control (RCQ) complex which is involved in proteolytic targeting of incomplete polypeptides prodduced by ribosome stalling. NEMF facilitates the recruitment of E3 ligase Listerin (LTN1) which ubiquitinates nascent polypeptide chains for subsequent proteasomal degradation. The author provide evidence that mice homozygous for Nemf missense mutations display progressive motor phenotypes, exhibit neurogenic atrophy and progressive axonal degeneration. A further NEMF-null mouse model displayed more severe phenotype (with heterozygous mice being unaffected). Equivalent mutations (of those in the above mouse model) in yeast (Rqc2) were shown to interfere with its ability to modify aberrant translation products with C-terminal tails which assist RQC-mediated protein degradation. Mutation of Ltn1 (belonging to the same protein control pathway) has been also shown to lead to neurodegeneration im mice. Overall NEMF is thought to play a role in neuronal translational homeostasis and the disorder to be mediated by dysfunction of the RQC pathway (normally protecting neurons against degeneration).; to: Biallelic (and possibly monoallelic) pathogenic variants in this gene are associated with DD/ID. Martin et al (2020 - PMID:32934225) report on 8 individuals from 6 families with a juvenile neuromuscular disease due to biallelic NEMF variants. (In one of these 8 cases it could not be ruled out that a de novo and maternally inherited variant were on the same allele, as phase was not determined). A ninth individual with similar presentation was found to harbor a single NEMF missense SNV as de novo event (due to a speculated dominant-negative effect). This individual had a similar presentation. Features incl. hypotonia (4/8 with biallelic variant (B) | 1/1 monoallelic (M) ), DD/ID (7/8B | 0/1M) with speech delay as universal feature (8/8B | 1/1M), axonal neuropathy (3/3B | 1/1M), ataxia (3/8B | 0/1M). Other findings included tremor (1/7B | 1/1M), abnormal brain imaging (2/6B / ?/1M), kyphosis/scoliosis (4/8B | 0/1M), respiratory distress (1/8B | 0/1M). NEMF (Rqc2 in yeast) encodes the nuclear export mediator factor, a component of the Ribosome-associated Quality Control (RCQ) complex which is involved in proteolytic targeting of incomplete polypeptides produced by ribosome stalling. NEMF facilitates the recruitment of E3 ligase Listerin (LTN1) which ubiquitinates nascent polypeptide chains for subsequent proteasomal degradation. The author provide evidence that mice homozygous for Nemf missense mutations display progressive motor phenotypes, exhibit neurogenic atrophy and progressive axonal degeneration. A further NEMF-null mouse model displayed more severe phenotype (with heterozygous mice being unaffected). Equivalent mutations (of those in the above mouse model) in yeast (Rqc2) were shown to interfere with its ability to modify aberrant translation products with C-terminal tails which assist RQC-mediated protein degradation. Mutation of Ltn1 (belonging to the same protein control pathway) has been also shown to lead to neurodegeneration in mice. Overall NEMF is thought to play a role in neuronal translational homeostasis and the disorder to be mediated by dysfunction of the RQC pathway (normally protecting neurons against degeneration). |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3053 | NEMF |
Konstantinos Varvagiannis changed review comment from: Biallelic (and possibly monoallelic) pathogenic variants in this gene are associated with DD/ID. Martin et al (2020 - PMID:32934225) report on 8 individuals from 6 families with a juvenile neuromuscular disease due to biallelic NEMF variants. (In one of these 8 cases it could not be ruled out that a de novo and maternally inherited variants were on the same allele, as phase was not been determined). A ninth individual with similar presentation was found to harbor a single NEMF missense SNV as de novo event (due to a speculated dominant-negative effect). This individual had a similar presentation. Features incl. hypotonia (4/8 with biallelic variant (B) | 1/1 monoallelic (M) ), DD/ID (7/8B | 0/1M) with speech delay as universal feature (8/8B | 1/1M), axonal neuropathy (3/3B | 1/1M), ataxia (3/8B | 0/1M). Other findings included tremor (1/7B | 1/1M), abnormal brain imaging (2/6B / ?/1M), kyphosis/scoliosis (4/8B | 0/1M), respiratory distress (1/8B | 0/1M). NEMF (Rqc2 in yeast) encodes the nuclear export mediator factor, a component of the Ribosome-associated Quality Control (RCQ) complex which is involved in proteolytic targeting of incomplete polypeptides prodduced by ribosome stalling. NEMF facilitates the recruitment of E3 ligase Listerin (LTN1) which ubiquitinates nascent polypeptide chains for subsequent proteasomal degradation. The author provide evidence that mice homozygous for Nemf missense mutations display progressive motor phenotypes, exhibit neurogenic atrophy and progressive axonal degeneration. A further NEMF-null mouse model displayed more severe phenotype (with heterozygous mice being unaffected). Equivalent mutations (of those in the above mouse model) in yeast (Rqc2) were shown to interfere with its ability to modify aberrant translation products with C-terminal tails which assist RQC-mediated protein degradation. Mutation of Ltn1 (belonging to the same protein control pathway) has been also shown to lead to neurodegeneration im mice. Overall NEMF is thought to play a role in neuronal translational homeostasis and the disorder to be mediated by dysfunction of the RQC pathway (normally protecting neurons against degeneration).; to: Biallelic (and possibly monoallelic) pathogenic variants in this gene are associated with DD/ID. Martin et al (2020 - PMID:32934225) report on 8 individuals from 6 families with a juvenile neuromuscular disease due to biallelic NEMF variants. (In one of these 8 cases it could not be ruled out that a de novo and maternally inherited variant were on the same allele, as phase was not determined). A ninth individual with similar presentation was found to harbor a single NEMF missense SNV as de novo event (due to a speculated dominant-negative effect). This individual had a similar presentation. Features incl. hypotonia (4/8 with biallelic variant (B) | 1/1 monoallelic (M) ), DD/ID (7/8B | 0/1M) with speech delay as universal feature (8/8B | 1/1M), axonal neuropathy (3/3B | 1/1M), ataxia (3/8B | 0/1M). Other findings included tremor (1/7B | 1/1M), abnormal brain imaging (2/6B / ?/1M), kyphosis/scoliosis (4/8B | 0/1M), respiratory distress (1/8B | 0/1M). NEMF (Rqc2 in yeast) encodes the nuclear export mediator factor, a component of the Ribosome-associated Quality Control (RCQ) complex which is involved in proteolytic targeting of incomplete polypeptides prodduced by ribosome stalling. NEMF facilitates the recruitment of E3 ligase Listerin (LTN1) which ubiquitinates nascent polypeptide chains for subsequent proteasomal degradation. The author provide evidence that mice homozygous for Nemf missense mutations display progressive motor phenotypes, exhibit neurogenic atrophy and progressive axonal degeneration. A further NEMF-null mouse model displayed more severe phenotype (with heterozygous mice being unaffected). Equivalent mutations (of those in the above mouse model) in yeast (Rqc2) were shown to interfere with its ability to modify aberrant translation products with C-terminal tails which assist RQC-mediated protein degradation. Mutation of Ltn1 (belonging to the same protein control pathway) has been also shown to lead to neurodegeneration im mice. Overall NEMF is thought to play a role in neuronal translational homeostasis and the disorder to be mediated by dysfunction of the RQC pathway (normally protecting neurons against degeneration). |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3053 | NEMF |
Konstantinos Varvagiannis changed review comment from: Biallelic (and possibly monoallelic) pathogenic variants in this gene are associated with DD/ID. Martin et al (2020 - PMID:32934225) report on 8 individuals from 6 families with a juvenile neuromuscular disease due to biallelic NEMF variants. (In one of these 8 cases it could be ruled out that the de novo and maternally inherited variants were on the same allele, as phase was not been determined). A ninth individual with similar presentation was found to harbor a single NEMF missense SNV as de novo event (due to a speculated dominant-negative effect). This individual had a similar presentation. Features incl. hypotonia (4/8 with biallelic variant (B) | 1/1 monoallelic (M) ), DD/ID (7/8B | 0/1M) with speech delay as universal feature (8/8B | 1/1M), axonal neuropathy (3/3B | 1/1M), ataxia (3/8B | 0/1M). Other findings included tremor (1/7B | 1/1M), abnormal brain imaging (2/6B / ?/1M), kyphosis/scoliosis (4/8B | 0/1M), respiratory distress (1/8B | 0/1M). NEMF (Rqc2 in yeast) encodes the nuclear export mediator factor, a component of the Ribosome-associated Quality Control (RCQ) complex which is involved in proteolytic targeting of incomplete polypeptides prodduced by ribosome stalling. NEMF facilitates the recruitment of E3 ligase Listerin (LTN1) which ubiquitinates nascent polypeptide chains for subsequent proteasomal degradation. The author provide evidence that mice homozygous for Nemf missense mutations display progressive motor phenotypes, exhibit neurogenic atrophy and progressive axonal degeneration. A further NEMF-null mouse model displayed more severe phenotype (with heterozygous mice being unaffected). Equivalent mutations (of those in the above mouse model) in yeast (Rqc2) were shown to interfere with its ability to modify aberrant translation products with C-terminal tails which assist RQC-mediated protein degradation. Mutation of Ltn1 (belonging to the same protein control pathway) has been also shown to lead to neurodegeneration im mice. Overall NEMF is thought to play a role in neuronal translational homeostasis and the disorder to be mediated by dysfunction of the RQC pathway (normally protecting neurons against degeneration).; to: Biallelic (and possibly monoallelic) pathogenic variants in this gene are associated with DD/ID. Martin et al (2020 - PMID:32934225) report on 8 individuals from 6 families with a juvenile neuromuscular disease due to biallelic NEMF variants. (In one of these 8 cases it could not be ruled out that a de novo and maternally inherited variants were on the same allele, as phase was not been determined). A ninth individual with similar presentation was found to harbor a single NEMF missense SNV as de novo event (due to a speculated dominant-negative effect). This individual had a similar presentation. Features incl. hypotonia (4/8 with biallelic variant (B) | 1/1 monoallelic (M) ), DD/ID (7/8B | 0/1M) with speech delay as universal feature (8/8B | 1/1M), axonal neuropathy (3/3B | 1/1M), ataxia (3/8B | 0/1M). Other findings included tremor (1/7B | 1/1M), abnormal brain imaging (2/6B / ?/1M), kyphosis/scoliosis (4/8B | 0/1M), respiratory distress (1/8B | 0/1M). NEMF (Rqc2 in yeast) encodes the nuclear export mediator factor, a component of the Ribosome-associated Quality Control (RCQ) complex which is involved in proteolytic targeting of incomplete polypeptides prodduced by ribosome stalling. NEMF facilitates the recruitment of E3 ligase Listerin (LTN1) which ubiquitinates nascent polypeptide chains for subsequent proteasomal degradation. The author provide evidence that mice homozygous for Nemf missense mutations display progressive motor phenotypes, exhibit neurogenic atrophy and progressive axonal degeneration. A further NEMF-null mouse model displayed more severe phenotype (with heterozygous mice being unaffected). Equivalent mutations (of those in the above mouse model) in yeast (Rqc2) were shown to interfere with its ability to modify aberrant translation products with C-terminal tails which assist RQC-mediated protein degradation. Mutation of Ltn1 (belonging to the same protein control pathway) has been also shown to lead to neurodegeneration im mice. Overall NEMF is thought to play a role in neuronal translational homeostasis and the disorder to be mediated by dysfunction of the RQC pathway (normally protecting neurons against degeneration). |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2982 | SLC16A2 | Zornitza Stark changed review comment from: Allan-Herndon-Dudley syndrome (AHDS) is an X-linked condition characterized by severely impaired intellectual development, dysarthria, athetoid movements, muscle hypoplasia, and spastic paraplegia. There is large phenotypic interfamilial and intrafamilial variability.; to: Allan-Herndon-Dudley syndrome (AHDS) is an X-linked condition characterized by severely impaired intellectual development, dysarthria, athetoid movements, muscle hypoplasia, and spastic paraplegia. There is large phenotypic interfamilial and intrafamilial variability. In a recent review of 24 affected individuals (PMID 31410843), 16 presented with profound developmental delay, three had severe intellectual disability with poor language and walking with an aid, four had moderate intellectual disability with language and walking abilities, and one had mild intellectual disability with hypotonia. Overall, eight had learned to walk, all had hypotonia, 17 had spasticity, 18 had dystonia, 12 had choreoathetosis, 19 had hypomyelination, and 10 had brain atrophy. Kyphoscoliosis (n=12), seizures (n=7), and pneumopathies (n=5) were the most severe complications. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2804 | ZNF407 |
Konstantinos Varvagiannis gene: ZNF407 was added gene: ZNF407 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ZNF407 was set to BOTH monoallelic and biallelic, autosomal or pseudoautosomal Publications for gene: ZNF407 were set to 24907849; 32737394; 23195952 Phenotypes for gene: ZNF407 were set to Global developmental delay; Intellectual disability Penetrance for gene: ZNF407 were set to unknown Review for gene: ZNF407 was set to AMBER Added comment: You may consider inclusion of this gene probably with amber rating (or green if the evidence for biallelic variants is considered sufficient). Biallelic variants: - Kambouris et al. (2014 - PMID: 24907849) described 2 brothers with severe DD and ID, born to first cousin parents. Homozygosity mapping, following other non-diagnostic investigations (incl. aCGH), revealed 4 major homozygosity intervals. Exome sequencing in one identified 5 variants within these intervals, ZNF407 (c.5054C>G, p.Ser1685Trp) being the best candidate, supported also by segregation studies. The authors commented that zinc finger proteins act as transcriptional regulators, with mutations in genes encoding for other zinc finger proteins interfering with normal brain development. - Zahra et al. (2020 - PMID: 32737394) report on 7 affected individuals (from 3 families) homozygous or compound heterozygous for ZNF407 variants. Features included hypotonia, DD and ID (in all) and variable occurrence of short stature (6/6), microcephaly (in at least 5), behavioural, visual problems and deafness. Linkage analysis in the first family revealed a 4.4 Mb shared homozygosity region and exome (30x) revealed a 3-bp duplication, confirmed by Sanger sequencing and segregating with the disease (NM_001146189:c.2814_2816dup, p.Val939dup). Affected subjects from the 2 other families were each found to be homozygous (c.2405G>T) or compound heterozygous (c.2884C>G, c.3642G>C) for other variants. Segregation was compatible in all families. Other studies were not performed. The authors comment than only the 3-bp duplication fullfilled ACMG criteria for classification as LP, the other variants being all formally classified as VUS (also due to in silico predictions predicting a LB effect). In addition, while several features such as DD/ID and short stature appeared to be frequent among all patients reported, Zahra et all comment that there was partial clinical overlap with the sibs described by Kambouris et al (additional variants?). Monoallelic disruption of ZNF407: - Ren et al (2013 - PMID: 23195952) described an 8 y.o. boy with ID and ASD. The boy was found to harbor a de novo translocation between chromosomes 3 and 18 [46,XY,t(3;18)(p13;q22.3)]. Array CGH did not reveal any P/LP CNV. Delineation of the breakpoints (FISH, long-range PCR) revealed that the chr18 breakpoint disrupted intron 3 of ZNF407 (isoform 1) with the other breakpoint within a gene-free region of exon 3. There was a loss of 4-8 nt in chr18 and 2-6 in chr3. Sequencing of ZNF407 did not reveal additional variants. RNA isolation in blood followed by RT-PCR studied expression of all 3 ZNF407 isoforms (the intronic region being shared by isoforms 1 and 2). Expression of isoform 1 was shown to be significantly reduced compared to controls. Isoform 2 was undetectable (in blood) while isoform 3 expression was similar to controls. Sequencing of 105 additional patients with similar clinical presentation (ID & ASD) revealed 2 further individuals with de novo missense variants. - Based on the discussion by Kambouris et al (PMID: 24907849 - cited literature not here reviewed) ZNF407 may be deleted in patients with congenital aural atresia due to deletion of a critical region of 18q22.3 (though TSHZ1 is responsible for this phenotype) or 18q- although such deletions span several other genes (cited PMID: 16639285). In one case the breakpoint was shown to be disrupting ZNF407 (cited PMID: 24092497). - The denovo db and Decipher (research variant tab) list few individuals with de novo ZNF407 SNVs although these do not seem to allow conclusions. https://denovo-db.gs.washington.edu/denovo-db/QueryVariantServlet?searchBy=Gene&target=ZNF407 https://decipher.sanger.ac.uk/search/ddd-research-variants/results?q=znf407 Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2750 | TBC1D2B |
Konstantinos Varvagiannis gene: TBC1D2B was added gene: TBC1D2B was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: TBC1D2B was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: TBC1D2B were set to 32623794 Phenotypes for gene: TBC1D2B were set to Global developmental delay; Intellectual disability; Seizures; Gingival overgrowth; Behavioral abnormality; Abnormality of the mandible; Abnormality of brain morphology; Abnormality of the eye; Hearing abnormality Penetrance for gene: TBC1D2B were set to Complete Review for gene: TBC1D2B was set to AMBER Added comment: Harms et al (2020 - PMID: 32623794) report on 3 unrelated individuals with biallelic pLoF TBC1D2B variants. Features included cognitive impairment (mild ID in one case, regression at the age of 12y in another, hypotonia and delayed milestones in a third aged 8m), seizures (3/3 - variable age of onset) and/or gingival overgrowth (2/3 - prior to initiation of AEDs). Other findings included behavioral abnormalities, mandibular anomalies, abnormal brain imaging and ophthalmologic or (rarely) audiometric evaluations. All were born to non-consanguineous couples and additional investigations were performed in some. Variants were identified by WES or trio WGS, with Sanger confirmation/compatible segregation analyses. In line with the pLoF variants, mRNA studies in fibroblasts from 2 unrelated affected individuals demonstrated significantly reduced (~80-90%) TBC1C2D mRNA levels compared to controls, restored following cycloheximide treatment. Protein was absent in patient fibroblasts. TBC-domain containing GTPase activating proteins are known as key regulators of RAB GTPase activity. TBC1D2B was shown to colocalize with RAB5-positive endocytic vesicles. CRISPR/Cas9-mediated ko of TBC1D2B in HeLa cells suggested a role in EGF receptor endocytosis and decreased cell viability of TBC1D2B-deficient HeLa cells upon serum deprivation. Genes encoding other TBC domain-containg GTPase-activating proteins, e.g. TBC1D7 and TBC1D20, TBC1D24 are associated with recessive neurodevelopmental disorders (with ID and/or seizures) and the pathophysiological defect in TBC1D2B-related disorder (deficit in vesicle trafficking and/or cell survival) is proposed to be similar to that of TBC1D24. Overall this gene can be considered for inclusion with amber/green rating in the ID panel and green in epilepsy panel. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2625 | YIF1B |
Konstantinos Varvagiannis gene: YIF1B was added gene: YIF1B was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: YIF1B was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: YIF1B were set to 32006098 Phenotypes for gene: YIF1B were set to Central hypotonia; Failure to thrive; Microcephaly; Global developmental delay; Intellectual disability; Seizures; Spasticity; Abnormality of movement Penetrance for gene: YIF1B were set to Complete Review for gene: YIF1B was set to GREEN Added comment: AlMuhaizea et al (2020 - PMID: 32006098) report on the phenotype of 6 individuals (from 5 families) with biallelic YIF1B truncating variants. Affected subjects presented hypotonia, failure to thrive, microcephaly (5/6), severe global DD and ID (as evident from best motor/language milestones achieved - Table S1) as well as features suggestive of a motor disorder (dystonia/spasticity/dyskinesia). Seizures were reported in 2 unrelated individuals (2/6). MRI abnormalities were observed in some with thin CC being a feature in 3. Variable initial investigations were performed including SNP CMA, MECP2, microcephaly / neurotransmitter disorders gene panel testing did not reveal P/LP variants. YIF1B variants were identified in 3 families within ROH. Following exome sequencing, affected individuals were found to be homozygous for truncating variants (4/5 families being consanguineous). The following 3 variants were identified (NM_001039672.2) : c.186dupT or p.Ala64fs / c.360_361insACAT or p.Gly121fs / c.598G>T or p.Glu200*. YIF1B encodes an intracellular transmembrane protein. It has been previously demonstrated that - similarly to other proteins of the Yip family being implicated in intracellular traffic between the Golgi - Yif1B is involved in the anterograde traffic pathway. Yif1B KO mice demonstrate a disorganized Golgi architecture in pyramidal hippocampal neurons (Alterio et al 2015 - PMID: 26077767). The rat ortholog interacts with serotonin receptor 1 (5-HT1AR) with colocalization of Yif1BB and 5-HT1AR in intermediate compartment vesicles and involvement of the former in intracellular trafficing/modulation of 5-HT1AR transport to dendrites (PMID cited: 18685031). Available mRNA and protein expression data (Protein Atlas) suggest that the gene is widely expressed in all tissues incl. neuronal cells. Immunochemistry data from the Human Brain Atlas also suggest that YIF1B is found in vesicles and localized to the Golgi apparatus. Immunohistochemistry in normal human brain tissue (cerebral cortex) demonstrated labeling of neuronal cells (Human Protein Atlas). Functional/network analysis of genes co-regulated with YIF1B based on available RNAseq data, suggest enrichement in in genes important for nervous system development and function. Please consider inclusion in other panels that may be relevant (e.g. microcephaly, etc). Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2138 | WDR4 |
Chirag Patel changed review comment from: Galloway-Mowat syndrome 6, OMIM #618347: 1 family with 2 sibs with GMS and compound heterozygous mutations in the WDR4 gene, segregated with the disorder in the family. Functional studies of the variants and studies of patient cells were not performed. 1 family with 1 child with GMS and compound heterozygous mutations in the WDR4 gene, segregated with the disorder in the family. Functional studies of the variants and studies of patient cells were not performed. 1 family with 4 sibs with GMS and homozygous splice site mutation in the WDR4 gene. Functional studies of the variant and studies of patient cells were not performed. Microcephaly, growth deficiency, seizures, and brain malformations; OMIM #618346: 2 unrelated patients with intrauterine growth retardation, postnatal growth deficiency with severe microcephaly, and poor or absent psychomotor development. Testing found the same homozygous missense mutation in the WDR4 gene, which segregated with the disorder in both families. Studies of patient cells and modeling of the corresponding mutation in yeast showed that the mutation caused a significant reduction in m(7)G46 methylation of specific tRNAs species, particularly at higher temperatures. This was associated with a growth defect in yeast, thus offering a potential mechanism for the growth defects observed in patients with the mutation. The findings suggested that abnormal tRNA modification is a major contributor to disease pathogenesis. Sources: Expert list; to: Galloway-Mowat syndrome 6, OMIM #618347: 1 family with 2 sibs with GMS and compound heterozygous mutations in the WDR4 gene, segregated with the disorder in the family. Functional studies of the variants and studies of patient cells were not performed. 1 family with 1 child with GMS and compound heterozygous mutations in the WDR4 gene, segregated with the disorder in the family. Functional studies of the variants and studies of patient cells were not performed. 1 family with 4 sibs with GMS and homozygous splice site mutation in the WDR4 gene. Functional studies of the variant and studies of patient cells were not performed. -------------------------------------------------------------------------------------------------------------------------------------- Microcephaly, growth deficiency, seizures, and brain malformations; OMIM #618346: 2 unrelated patients with intrauterine growth retardation, postnatal growth deficiency with severe microcephaly, and poor or absent psychomotor development. Testing found the same homozygous missense mutation in the WDR4 gene, which segregated with the disorder in both families. Studies of patient cells and modeling of the corresponding mutation in yeast showed that the mutation caused a significant reduction in m(7)G46 methylation of specific tRNAs species, particularly at higher temperatures. This was associated with a growth defect in yeast, thus offering a potential mechanism for the growth defects observed in patients with the mutation. The findings suggested that abnormal tRNA modification is a major contributor to disease pathogenesis. Sources: Expert list |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2137 | WDR4 |
Chirag Patel gene: WDR4 was added gene: WDR4 was added to Intellectual disability syndromic and non-syndromic. Sources: Expert list Mode of inheritance for gene: WDR4 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: WDR4 were set to PubMed: 26416026, 30079490, 29597095, 28617965 Phenotypes for gene: WDR4 were set to Galloway-Mowat syndrome 6, OMIM #618347; Microcephaly, growth deficiency, seizures, and brain malformations, OMIM #618346 Review for gene: WDR4 was set to GREEN Added comment: Galloway-Mowat syndrome 6, OMIM #618347: 1 family with 2 sibs with GMS and compound heterozygous mutations in the WDR4 gene, segregated with the disorder in the family. Functional studies of the variants and studies of patient cells were not performed. 1 family with 1 child with GMS and compound heterozygous mutations in the WDR4 gene, segregated with the disorder in the family. Functional studies of the variants and studies of patient cells were not performed. 1 family with 4 sibs with GMS and homozygous splice site mutation in the WDR4 gene. Functional studies of the variant and studies of patient cells were not performed. Microcephaly, growth deficiency, seizures, and brain malformations; OMIM #618346: 2 unrelated patients with intrauterine growth retardation, postnatal growth deficiency with severe microcephaly, and poor or absent psychomotor development. Testing found the same homozygous missense mutation in the WDR4 gene, which segregated with the disorder in both families. Studies of patient cells and modeling of the corresponding mutation in yeast showed that the mutation caused a significant reduction in m(7)G46 methylation of specific tRNAs species, particularly at higher temperatures. This was associated with a growth defect in yeast, thus offering a potential mechanism for the growth defects observed in patients with the mutation. The findings suggested that abnormal tRNA modification is a major contributor to disease pathogenesis. Sources: Expert list |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1872 | COL1A2 | Zornitza Stark Phenotypes for gene: COL1A2 were changed from to Ehlers-Danlos syndrome, arthrochalasia type, 2, MIM# 617821; Ehlers-Danlos syndrome, cardiac valvular type, MIM# 225320; Osteogenesis imperfecta, type II, MIM# 166210; Osteogenesis imperfecta, type III, MIM# 259420; Osteogenesis imperfecta, type IV, MIM# 166220 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1869 | COL1A2 | Zornitza Stark reviewed gene: COL1A2: Rating: RED; Mode of pathogenicity: None; Publications: ; Phenotypes: Ehlers-Danlos syndrome, arthrochalasia type, 2, MIM# 617821, Ehlers-Danlos syndrome, cardiac valvular type, MIM# 225320, Osteogenesis imperfecta, type II, MIM# 166210, Osteogenesis imperfecta, type III, MIM# 259420, Osteogenesis imperfecta, type IV, MIM# 166220; Mode of inheritance: BOTH monoallelic and biallelic, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1361 | FBXL3 |
Chirag Patel gene: FBXL3 was added gene: FBXL3 was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: FBXL3 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: FBXL3 were set to PubMed: 30481285 Phenotypes for gene: FBXL3 were set to Intellectual developmental disorder with short stature, facial anomalies, and speech defects; OMIM #606220 Review for gene: FBXL3 was set to AMBER Added comment: 3 unrelated families with 8 affected individuals with ID, DD, short stature and mild facial dysmorphism, and with homozygous mutations in FBXL3. Segregated with the disorder in all 3 families. Functional studies of the variants and studies of patient cells were not performed. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1335 | NCAPD2 |
Chirag Patel gene: NCAPD2 was added gene: NCAPD2 was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: NCAPD2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: NCAPD2 were set to PMID: 31056748; 27737959; 28097321 Phenotypes for gene: NCAPD2 were set to ?Microcephaly 21, primary, autosomal recessive; OMIM #617983 Review for gene: NCAPD2 was set to AMBER Added comment: 1 family with 2 sibs with microcephaly and ID, and homozygous NCAPD2 mutation, which segregated with disease. No functional evidence. 1 family with 1 affected and homozygous NCAPD2 mutation, which segregated with disease. Patient fibroblasts showed impaired chromosome segregation and abnormal recovery from mitotic condensation compared to controls. 1 family with 2 sibs with microcephaly, growth retardation, and ID, and homozygous NCAPD2 mutation, which segregated with disease. Functional studies of the variants and studies of patient cells were not performed. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1322 | PIGB |
Chirag Patel gene: PIGB was added gene: PIGB was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: PIGB was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PIGB were set to PubMed: 31256876 Phenotypes for gene: PIGB were set to Epileptic encephalopathy, early infantile, 80; OMIM #618580 Review for gene: PIGB was set to GREEN Added comment: 10 unrelated families with biallelic mutations in PIGB, with global DD and/or ID, and seizures. Two had polymicrogyria, 4 had a peripheral neuropathy, and 2 had a clinical diagnosis of DOORS syndrome. Patient lymphocytes and fibroblasts showed variably decreased levels of cell surface GPI-anchored proteins, including CD16 and CD59. In vitro functional expression studies performed with some of the mutations in PIGB-null CHO cells showed that the mutant proteins were unable to fully restore expression of GPI-anchored surface proteins, consistent with a loss of function, although the mutations had variable effects. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1317 | PISD |
Chirag Patel changed review comment from: 4 individuals in 2 unrelated but consanguineous families from Portugal and Brazil affected by early-onset retinal degeneration, sensorineural hearing loss, microcephaly, intellectual disability, and skeletal dysplasia with scoliosis and short stature (Liberfarb syndrome). Affected individuals shared a homozygous 10-bp deletion immediately upstream of the last exon of the PISD gene. In HEK293T cells, this variant led to aberrant splicing of PISD transcripts. Sources: Literature; to: 4 individuals in 2 unrelated but consanguineous families from Portugal and Brazil affected by early-onset retinal degeneration, sensorineural hearing loss, microcephaly, intellectual disability, and skeletal dysplasia with scoliosis and short stature (Liberfarb syndrome). Affected individuals shared a homozygous 10-bp deletion immediately upstream of the last exon of the PISD gene. In HEK293T cells, this variant led to aberrant splicing of PISD transcripts. 1 family with 2 sisters with congenital cataracts, short stature, and white matter changes identified compound heterozygous variants in the PISD gene. Decreased conversion of phosphatidylserine to PE in patient fibroblasts is consistent with impaired phosphatidylserine decarboxylase (PISD) enzyme activity. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1317 | PISD |
Chirag Patel gene: PISD was added gene: PISD was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: PISD was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PISD were set to PMID: 31263216 Phenotypes for gene: PISD were set to no OMIM number yet. Review for gene: PISD was set to AMBER Added comment: 4 individuals in 2 unrelated but consanguineous families from Portugal and Brazil affected by early-onset retinal degeneration, sensorineural hearing loss, microcephaly, intellectual disability, and skeletal dysplasia with scoliosis and short stature (Liberfarb syndrome). Affected individuals shared a homozygous 10-bp deletion immediately upstream of the last exon of the PISD gene. In HEK293T cells, this variant led to aberrant splicing of PISD transcripts. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1275 | ZMIZ1 |
Chirag Patel gene: ZMIZ1 was added gene: ZMIZ1 was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: ZMIZ1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: ZMIZ1 were set to PubMed: 30639322 Phenotypes for gene: ZMIZ1 were set to Neurodevelopmental disorder with dysmorphic facies and distal skeletal anomalies; OMIM #618659 Review for gene: ZMIZ1 was set to GREEN Added comment: 28 families with spectrum of neurodevelopmental features (including ID, ASD, and ADHD) due to de novo ZNF292 variants (1 family inherited). No functional evidence of specific variants, but ZNF292 is highly expressed in the developing human brain. 14 unrelated patients with neurodevelopmental disorder with dysmorphic facies and distal skeletal anomalies, and de novo heterozygous mutations in the ZMIZ1 gene. Transfection of 3 variants (T300M, c.3112dupA, and K91R) into HEK293T cells resulted in decreased induction of luciferase activity compared to wildtype (although the change for K91R was not statistically significant), suggesting impaired coactivation activity of the mutant proteins. Electroporation of these 3 mutants into progenitor cells in the ventricular zone of embryonic mice cortices resulted in defective neuronal migration to the cortex, as well as morphologic abnormalities of the neurons manifest as rounded cells with aberrantly oriented processes. These findings suggested that the ZMIZ1 mutations disrupted proper neuronal polarization and neuronal migration in the developing cortex. Functional studies of the other variants and additional studies of patient cells were not performed. Sources: Literature |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1267 | SP7 | Zornitza Stark Phenotypes for gene: SP7 were changed from to Osteogenesis imperfecta, type XII; OMIM # 613849 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1211 | SP7 | Chirag Patel reviewed gene: SP7: Rating: RED; Mode of pathogenicity: None; Publications: ; Phenotypes: Osteogenesis imperfecta, type XII, OMIM # 613849; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.524 | TRMT1 |
Chirag Patel edited their review of gene: TRMT1: Added comment: 4 families reported: -1 consanguineous Iranian family with 5 individuals with nonsyndromic moderate to severe impaired intellectual development. -1 consanguineous Iranian family with 3 adult brothers with global developmental delay and moderately delayed intellectual development -2 unrelated Pakistani families with 4 patients with impaired intellectual development. All with homozygous mutations in the TRMT1 gene which segregated with the disorder in the families, but functional studies of the variants were not performed.; Changed publications: PMID: 30289604, 26308914, 21937992 |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.394 | VPS37A |
Chirag Patel changed review comment from: ID reported in this type of HSP in 2 families. Zivony-Elboum et al. (2012) reported 9 patients from 2 Arab Moslem families with early-onset spastic paraplegia. Affected individuals showed developmental and motor delay during the first 2 years of life. They had unsteadiness in standing and difficulty walking. All affected children presented with spasticity in the lower limbs that progressed to the upper extremities. All had mild to moderate cognitive and speech delay.; to: ID reported in this type of HSP in 2 families. Zivony-Elboum et al. (2012) reported 9 patients from 2 Arab Moslem families with early-onset spastic paraplegia. Affected individuals showed developmental and motor delay during the first 2 years of life. They had unsteadiness in standing and difficulty walking. All affected children presented with spasticity in the lower limbs that progressed to the upper extremities. All had mild to moderate cognitive and speech delay. Functional studied performed. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.348 | WNT1 | Chirag Patel reviewed gene: WNT1: Rating: GREEN; Mode of pathogenicity: None; Publications: PubMed: 26671912; Phenotypes: Osteogenesis imperfecta, type XV, OMIM# 615220; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.348 | WNT1 |
Chirag Patel Source Genetic Health Queensland was removed from WNT1. Source Expert list was added to WNT1. Mode of inheritance for gene WNT1 was changed from Unknown to BIALLELIC, autosomal or pseudoautosomal Phenotypes for gene: WNT1 were changed from to Osteogenesis imperfecta, type XV; OMIM# 615220 |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.249 | FTL | Zornitza Stark Phenotypes for gene: FTL were changed from to Neurodegeneration with brain iron accumulation 3, MIM#606159; Hyperferritinemia-cataract syndrome, MIM#600886; L-ferritin deficiency, dominant and recessive, MIM#615604 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.246 | FTL | Zornitza Stark reviewed gene: FTL: Rating: RED; Mode of pathogenicity: None; Publications: ; Phenotypes: Neurodegeneration with brain iron accumulation 3, MIM#606159, Hyperferritinemia-cataract syndrome, MIM#600886, L-ferritin deficiency, dominant and recessive, MIM#615604; Mode of inheritance: BOTH monoallelic and biallelic, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.176 | ERF | Zornitza Stark Marked gene: ERF as ready | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.176 | ERF | Zornitza Stark Gene: erf has been classified as Red List (Low Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.176 | ERF | Zornitza Stark Phenotypes for gene: ERF were changed from to Chitayat syndrome, MIM#617180; Craniosynostosis 4, MIM#600775 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.175 | ERF | Zornitza Stark Mode of inheritance for gene: ERF was changed from Unknown to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.174 | ERF | Zornitza Stark Classified gene: ERF as Red List (low evidence) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.174 | ERF | Zornitza Stark Gene: erf has been classified as Red List (Low Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.173 | ERF | Zornitza Stark reviewed gene: ERF: Rating: RED; Mode of pathogenicity: None; Publications: ; Phenotypes: Chitayat syndrome, MIM#617180, Craniosynostosis 4, MIM#600775; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.63 | CRTAP | Zornitza Stark Phenotypes for gene: CRTAP were changed from to Osteogenesis imperfecta, type VII, MIM#610682 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.60 | CRTAP | Zornitza Stark reviewed gene: CRTAP: Rating: RED; Mode of pathogenicity: None; Publications: ; Phenotypes: Osteogenesis imperfecta, type VII, MIM#610682; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.0 | ERF |
Zornitza Stark gene: ERF was added gene: ERF was added to Intellectual disability, syndromic and non-syndromic_GHQ. Sources: Expert Review Green,Genetic Health Queensland Mode of inheritance for gene: ERF was set to Unknown |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||