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| Intellectual disability syndromic and non-syndromic v1.96 | CDKL1 |
Sarah Milton gene: CDKL1 was added gene: CDKL1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: CDKL1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: CDKL1 were set to PMID: 40088891 Phenotypes for gene: CDKL1 were set to Neurodevelopmental disorder, MONDO:0700092, CDKL1-related Mode of pathogenicity for gene: CDKL1 was set to Other Review for gene: CDKL1 was set to AMBER Added comment: CDKL1 encodes a cyclin dependent kinase of which there are CDKL1-5 in humans. (CDKL5 has been associated with a neurodevelopmental disorder previously.) Bereshneh et al describe 2 individuals with a neurodevelopmental disorder with de novo variants in CDKL1 sourced from databases containing individuals with neurodevelopmental disorders, no additional phenotypic information was provided. Both variants were missense and present in the population (c.505C>T - 13 heterozygotes in gnomad 4, c.344T>C - 2 heterozygotes gnomad 4). Both missense variants were located in the kinase domain and dominant negative mechanism was postulated based on drosophilia studies. Functional studies in drosphilia showed variants seen in probands partially rescued a loss of function model however overexpression of transcripts containing the variants resulted in a more severe phenotype suggesting dominant negative. Authors also noted the larger than expected number of LOF variants in gnomad for the disease to be caused by this mechanism. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v1.96 | CDKL2 |
Sarah Milton gene: CDKL2 was added gene: CDKL2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: CDKL2 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: CDKL2 were set to PMID: 40088891 Phenotypes for gene: CDKL2 were set to Neurodevelopmental disorder, MONDO:0700092, CDKL2-related Penetrance for gene: CDKL2 were set to Complete Mode of pathogenicity for gene: CDKL2 was set to Other Review for gene: CDKL2 was set to AMBER Added comment: CDKL2 encodes a cyclin dependent kinase of which there are CDKL1-5 in humans. (CDKL5 has been associated with a neurodevelopmental disorder previously.) Bereshneh et al describe 5 individuals with a neurodevelopmental disorder with de novo variants in CDKL2. 3 variants were missense, 1 was an in frame single amino acid deletion. 2 of the individuals described were monozygotic twins who were born at 30/40 and also had PVL on neuroimaging. Phenotype included GDD (5/5) - severity not described, speech impairment (5/5), motor impairment (4/5), epilepsy (3/5), ID (3/5), IUGR (3/5), poor growth postnatally (3/5), GI/feeding issues (3/5), tone abnormality (3/5) Missense variants were located in the kinase domain and dominant negative mechanism was postulated based on drosophilia studies. Functional studies in drosphilia showed variants seen in probands did not completely rescue a loss of function model, as well as this, overexpression of transcripts containing the variants resulted in a more severe phenotype suggesting dominant negative. Authors also noted the larger than expected number of LOF variants in gnomad for the disease to be caused by this mechanism. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v1.55 | ITGAV |
Zornitza Stark gene: ITGAV was added gene: ITGAV was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ITGAV was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: ITGAV were set to 39526957 Phenotypes for gene: ITGAV were set to Syndromic disease, MONDO:0002254, ITGAV-related Review for gene: ITGAV was set to AMBER Added comment: Three unrelated families reported: two with affected children (one hmz missense; other compound het LoF with missense) and one family with four affected fetuses. Clinical features included brain and eye anomalies and IBD/immune dysregulation. TGF-beta signalling pathway affected. The deletion of itgav in zebrafish recapitulated patient phenotypes including retinal and brain defects and the loss of microglia in early development as well as colitis in juvenile zebrafish with reduced SMAD3 expression and transcriptional regulation. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v1.23 | RUNX1T1 |
Chirag Patel gene: RUNX1T1 was added gene: RUNX1T1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: RUNX1T1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: RUNX1T1 were set to PMID: 39568205, 19172993, 22644616, 31223340 Phenotypes for gene: RUNX1T1 were set to Neurodevelopmental disorder MONDO:0700092 Review for gene: RUNX1T1 was set to GREEN Added comment: RUNX1T1 encodes a transcription regulator for hematopoietic genes and is well-known for its involvement in hematologic malignancies. Germline RUNX1T1 variants may also play a role in human congenital neurodevelopmental disorders. PMID: 39568205 3 unrelated individuals with developmental delay, learning disability, ASD, ADHD, and dysmorphism (1 x heart defects). Trio WES identified de novo variants in RUNX1T1 gene (1 x nonsense variant in 5' region [p.Gln36Ter], 2 x missense variants in C-terminus [p.Gly412Arg and p.His521Tyr]). PMID: 19172993 1 individual with mild-moderate ID and congenital heart disease, and chromosome t(5;8)(q32;q21.3) translocation. Molecular characterization revealed that one of the break points was within the RUNX1T1 gene. Analysis of RUNX1T1 expression in human embryonic and fetal tissues suggests a role of RUNX1T1 in brain and heart development. PMID: 22644616 1 individual with mild ID and dysmorphism, and de novo deletion exons 3-7 in RUNX1T1. PMID: 31223340 1 individual with ID, anaemia, atrial septal defect, dysmorphism, and seizures. Found to have a 2.1 Mb deletion at 8q21.3q22.1 involving entire RUNX1T1 gene (and 2 adjacent genes - SLC26A7 and TRIQK), and a benign familial 4.3 Mb duplication at 1p22.1p21.3 (present in unaffected healthy brother). Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v1.10 | MGA |
Zornitza Stark gene: MGA was added gene: MGA was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: MGA was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: MGA were set to 39600096; 20044811 Phenotypes for gene: MGA were set to Syndromic disease, MONDO:0002254, MGA-related Review for gene: MGA was set to GREEN Added comment: Three individuals with de novo LoF variants reported in individuals with ID and congenital anomalies. Zebrafish model supports role of this transcription factor in organogenesis. Note there are previous, less clear reports of association with NDD/CHD. Gene is constrained for LoF variants in gnomad v4; however, note there are ~30 individuals with LoF variants present. Borderline Green/Amber. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.6626 | LINC01578 |
Zornitza Stark gene: LINC01578 was added gene: LINC01578 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature new gene name tags were added to gene: LINC01578. Mode of inheritance for gene: LINC01578 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: LINC01578 were set to 39442041 Phenotypes for gene: LINC01578 were set to Neurodevelopmental disorder, MONDO:0700092, CHASERR-related Review for gene: LINC01578 was set to GREEN Added comment: CHASERR encodes a human long noncoding RNA (lncRNA) adjacent to CHD2, a coding gene in which de novo loss-of-function variants cause developmental and epileptic encephalopathy. Three unrelated children reported with a syndromic, early-onset neurodevelopmental disorder, each of whom had a de novo deletion in the CHASERR locus. The children had severe encephalopathy, shared facial dysmorphisms, cortical atrophy, and cerebral hypomyelination - a phenotype that is distinct from the phenotypes of patients with CHD2 haploinsufficiency. CHASERR deletion results in increased CHD2 protein abundance in patient-derived cell lines and increased expression of the CHD2 transcript in cis, indicating bidirectional dosage sensitivity in human disease. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.6062 | CRNKL1 |
Mark Cleghorn gene: CRNKL1 was added gene: CRNKL1 was added to Intellectual disability syndromic and non-syndromic. Sources: Other Mode of inheritance for gene: CRNKL1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Phenotypes for gene: CRNKL1 were set to complex neurodevelopmental disorder MONDO:0100038 Penetrance for gene: CRNKL1 were set to Complete Review for gene: CRNKL1 was set to GREEN Added comment: Unpublished, presented at ESHG June 2024 - Louise Bicknell, University of Otago NZ 8 unrelated families via gene matcher with rare, de novo, missense variants in CRNKL1 severe microcephaly (all, -8 to -11 SD) ID/epilepsy pontocerebellar hypoplasia (6/8) simplified gyration (8/8) 7 variants are missense at p.Arg267 residue 1 variant missense at p.Arg301 RNA-seq on patient fibroblasts - no alteration in gene expression Zebrafish homolog of Arg267 and Arg301 - mimics observed phenotype (reduced brain development), increased in embryo apoptosis RNQ seq on affected zebrafish embryos - transcriptome strongly disrupted Splicing analysis in progress CRKNL1 supports U6 structure in spliceosome Sources: Other |
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| 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 |
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| Intellectual disability syndromic and non-syndromic v0.5706 | ZFX |
Sarah Leigh gene: ZFX was added gene: ZFX was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ZFX was set to X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males) Publications for gene: ZFX were set to 26350204; 26740508; 38325380 Phenotypes for gene: ZFX were set to X-linked neurodevelopmental disorder with recurrent facial gestalt Review for gene: ZFX was set to GREEN Added comment: To date, germline variants in ZFX have not been associated with a phenotype in OMIM or Gen2Phen. A single ZFX variant has been associated with a neurodevelopmental disorder, that has a Rett syndrome-like phenotype disorder, in a 14 year old male. The ZFX variant was allelic with another X-linked variant in SHROOM4. These variants were inherited from the mother, who had random X inactivation pattern (PMID: 26740508). PMID: 38325380 reports 11 ZFX variants in 18 subjects from 16 unrelated families (14 males and 4 females) with an X-linked neurodevelopmental disorder with recurrent facial gestalt. Seven variants were truncating and the remaining were missense variants within the Zinc finger array. In the pedigree of family 6 (figure 3, PMID: 38325380), it was apparent that there were female carriers of the ZFX variant (GRCh38 chrX: 24229396A>G, c.2438A>G, p.Tyr774Cys) with hyperparathyroidism and two affected males and one affected female, with the neurodevelopmental disorder. It appeared that skewed X-inactivation in the female carriers was responsible for the different phenotypic features. The association between ZFX variants and a novel neurodevelopmental disorder, was further supported by functional studies showing altered transcriptional activity in missense variants and altered behavior in a zebrafish loss-of-function model. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5661 | MAX |
Rylee Peters gene: MAX was added gene: MAX was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: MAX was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: MAX were set to 38141607 Phenotypes for gene: MAX were set to Syndromic disease (MONDO:0002254), MAX-related Review for gene: MAX was set to GREEN Added comment: Three individuals who each share a recurrent de novo germline variant in the MAX gene, resulting in a p.Arg60Gln substitution in the loop of the b-HLH-LZ domain. Affected individuals have a complex disorder consisting primarily of macrocephaly, polydactyly, and delayed ophthalmic development. Other phenotypes reported include intellectual disability, perianal abscesses, pectus carinatum, hypospadias, renal agenesis, single umbilical artery, flattened thoracic vertebrae. Functional analysis of the p.Arg60Gln variant shows a significant increase in CCND2 protein and a more efficient heterodimerization with c-Myc resulting in an increase in transcriptional activity of c-Myc. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5603 | AGPAT3 |
Ee Ming Wong changed review comment from: - Single consanguineous family with four individuals with severe intellectual disability and retinitis pigmentosa - All affected individuals were homozygous for a nonsense variant in AGPAT3, healthy unaffected individuals who were tested were heterozygous for the variant - Overexpression of mutant transcript revealed absence of AGPAT3 protein compared to WT transcript via Western blot analysis - KO AGPAT3 mouse demonstrated impaired neuronal migration Sources: Literature; to: - Single consanguineous family with four individuals with severe intellectual disability and retinitis pigmentosa - All affected individuals were homozygous for a nonsense variant in AGPAT3, healthy unaffected individuals who were tested were heterozygous for the variant - Overexpression of mutant transcript revealed absence of AGPAT3 protein compared to WT transcript via Western blot analysis - KO AGPAT3 mouse demonstrated impaired neuronal migration Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5602 | AGPAT3 |
Ee Ming Wong gene: AGPAT3 was added gene: AGPAT3 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: AGPAT3 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: AGPAT3 were set to PMID: 37821758 Phenotypes for gene: AGPAT3 were set to Neurodevelopmental disorder (MONDO#0700092), AGPAT3-related Review for gene: AGPAT3 was set to GREEN gene: AGPAT3 was marked as current diagnostic Added comment: - Single consanguineous family with four individuals with severe intellectual disability and retinitis pigmentosa - All affected individuals were homozygous for a nonsense variant in AGPAT3, healthy unaffected individuals who were tested were heterozygous for the variant - Overexpression of mutant transcript revealed absence of AGPAT3 protein compared to WT transcript via Western blot analysis - KO AGPAT3 mouse demonstrated impaired neuronal migration Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5601 | DLG2 |
Elena Savva gene: DLG2 was added gene: DLG2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: DLG2 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: DLG2 were set to PMID: 37860969 Phenotypes for gene: DLG2 were set to Intellectual disability (MONDO#0001071), DLG2-related Review for gene: DLG2 was set to AMBER Added comment: PMID: 37860969 - 13 patients from 10 families with neurodevelopmental disorders, dysmorphic features and intragenic deletions including both exonic (minimal affect all transcripts) and UTR regions. Majority of variants were inherited, some de novo. But many NMD PTCs in gnomAD (some looking messy, in noncanonical transcript etc.) Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5234 | POU3F2 |
Sarah Pantaleo gene: POU3F2 was added gene: POU3F2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: POU3F2 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: POU3F2 were set to PMID: 37207645 Phenotypes for gene: POU3F2 were set to Autism spectrum disorder, NDD, and adolescent-onset obesity Penetrance for gene: POU3F2 were set to unknown Mode of pathogenicity for gene: POU3F2 was set to Other Review for gene: POU3F2 was set to GREEN Added comment: We associate ultra-rare variants in POU3F2, encoding a central nervous system transcription factor, with syndromic obesity and neurodevelopment delay in 12 individuals. Demonstrate variant pathogenicity through in vitro analysis. Used exome sequencing, GeneMatcher and Genomics England 100,000 Genomes Project rare disease database. Both truncating and missense variants in over 10 individuals sharing autism spectrum disorder, NDD, and adolescent-onset obesity (may have had other features eg. CAKUT in 2 individuals, diabetes in two) . Affected individuals presented with low-to-normal birth weight and infantile feeding difficulties but developed insulin resistance and hyperplasia during childhood. With the exception of an early truncating variant, the variants showed adequate nuclear translocation but overall disturbed DNA-binding ability and promoter activation. Variants absent from population and clinical databases. Almost all constituted putatively non-inherited de novo variants (8/10). Functional studies provide evidence for loss of function in eight and gain of function in one obesity-associated POU3F2 variant. One variant did not impact POU3F2-promoter activation, leaving the possibility for further path-mechanisms. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5201 | CRIPT | Zornitza Stark Marked gene: CRIPT as ready | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5201 | CRIPT | Zornitza Stark Gene: cript has been classified as Green List (High Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5201 | CRIPT | Zornitza Stark Classified gene: CRIPT as Green List (high evidence) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5201 | CRIPT | Zornitza Stark Gene: cript has been classified as Green List (High Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5198 | CRIPT |
Karina Sandoval commented on gene: CRIPT: PMID: 37013901 identified 6 individuals with Rothmund-Thomson syndrome characterised by poikiloderma, sparse hair, small stature, skeletal defects, cancer, cataracts, resembling features of premature aging. Two new variants identified and 4 were already published. 5 were hom, 1 was chet, all with different variants. All CRIPT individuals fulfilled the diagnostic criteria for RTS, and additionally had neurodevelopmental delay and seizures. CRIPT-deficient fibroblasts showed an unremarkable mitotic progression and unremarkable number of mitotic errors, c.132del p.(Ala45Glyfs*82), hom c.227G>A, p.(Cys76Tyr), hom c.133_134insGG,p.(Ala45Glyfs*82),hom c.141del p.(Phe47Leufs*84), hom c.8G>A p.(Cys3Tyr), 1,331 bp del exon 1, chet c.7_8del; p.(Cys3Argfs*4), hom |
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| Intellectual disability syndromic and non-syndromic v0.5198 | CRIPT |
Karina Sandoval gene: CRIPT was added gene: CRIPT was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: CRIPT was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: CRIPT were set to PMID: 37013901 Phenotypes for gene: CRIPT were set to Short stature with microcephaly and distinctive facies (MIM#615789) : Rothmund-Thomson syndrome MONDO:0010002 Review for gene: CRIPT was set to GREEN Added comment: Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5139 | CDK16 |
Belinda Chong changed review comment from: Total of 3 families with ID 1 with ASD. PMID 36323681: Identified a nonsense variant (c.961 G > T, p.(Glu321*)) in a 42-year-old patient with ID and spasticity. A missense variant (c.1039G > T, p.(Gly347Cys)) affecting a highly conserved amino acid of the kinase domain (CADD PHRED score: 32) was identified by genome sequencing in a male patient with ID, ASD, and epilepsy, whose family history was compatible with X-linked inheritance. PMID 31981491: In addition, a nonsense variant (c.46C > T, p.(Arg16*)) was recently reported in a patient with ASD. PMID 25644381: Single family described in this manuscript describing multiple candidate genes for XLID.; to: 3 families with ID 1 with ASD. PMID 36323681: Identified a nonsense variant (c.961 G > T, p.(Glu321*)) in a 42-year-old patient with ID and spasticity. A missense variant (c.1039G > T, p.(Gly347Cys)) affecting a highly conserved amino acid of the kinase domain (CADD PHRED score: 32) was identified by genome sequencing in a male patient with ID, ASD, and epilepsy, whose family history was compatible with X-linked inheritance. PMID 31981491: In addition, a nonsense variant (c.46C > T, p.(Arg16*)) was recently reported in a patient with ASD. PMID 25644381: Single family described in this manuscript describing multiple candidate genes for XLID. |
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| Intellectual disability syndromic and non-syndromic v0.5139 | CDK16 |
Belinda Chong changed review comment from: Total of 3 families with ID i with ASD. PMID 36323681: Identified a nonsense variant (c.961 G > T, p.(Glu321*)) in a 42-year-old patient with ID and spasticity. A missense variant (c.1039G > T, p.(Gly347Cys)) affecting a highly conserved amino acid of the kinase domain (CADD PHRED score: 32) was identified by genome sequencing in a male patient with ID, ASD, and epilepsy, whose family history was compatible with X-linked inheritance. PMID 31981491: In addition, a nonsense variant (c.46C > T, p.(Arg16*)) was recently reported in a patient with ASD. PMID 25644381: Single family described in this manuscript describing multiple candidate genes for XLID.; to: Total of 3 families with ID 1 with ASD. PMID 36323681: Identified a nonsense variant (c.961 G > T, p.(Glu321*)) in a 42-year-old patient with ID and spasticity. A missense variant (c.1039G > T, p.(Gly347Cys)) affecting a highly conserved amino acid of the kinase domain (CADD PHRED score: 32) was identified by genome sequencing in a male patient with ID, ASD, and epilepsy, whose family history was compatible with X-linked inheritance. PMID 31981491: In addition, a nonsense variant (c.46C > T, p.(Arg16*)) was recently reported in a patient with ASD. PMID 25644381: Single family described in this manuscript describing multiple candidate genes for XLID. |
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| Intellectual disability syndromic and non-syndromic v0.5138 | CDK16 |
Belinda Chong commented on gene: CDK16: Total of 3 families with ID i with ASD. PMID 36323681: Identified a nonsense variant (c.961 G > T, p.(Glu321*)) in a 42-year-old patient with ID and spasticity. A missense variant (c.1039G > T, p.(Gly347Cys)) affecting a highly conserved amino acid of the kinase domain (CADD PHRED score: 32) was identified by genome sequencing in a male patient with ID, ASD, and epilepsy, whose family history was compatible with X-linked inheritance. PMID 31981491: In addition, a nonsense variant (c.46C > T, p.(Arg16*)) was recently reported in a patient with ASD. PMID 25644381: Single family described in this manuscript describing multiple candidate genes for XLID. |
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| Intellectual disability syndromic and non-syndromic v0.5134 | TRA2B |
Elena Savva gene: TRA2B was added gene: TRA2B was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: TRA2B was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: TRA2B were set to PMID: 36549593 Phenotypes for gene: TRA2B were set to Neurodevelopmental disorder, TRA2B-related (MONDO#0700092) Review for gene: TRA2B was set to GREEN Added comment: PMID: 36549593 - 12 individuals with ID and dev delay. Additional features include infantile spams 6/12, hypotonia 12/12, dilated brain ventricles 6/12, microcephaly 5/12 - All variants result in the loss of 1/2 transcripts (start-losses or PTCs upstream of a second translation start position). Shorter transcript expression is increased, longer transcript expression is decreased. - Apparently het mice K/O are normal, but complete K/O cannot develop embryonically. - DN mechanism suggested Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5031 | KIF26A |
Chirag Patel gene: KIF26A was added gene: KIF26A was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: KIF26A was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: KIF26A were set to PMID: 36228617 Phenotypes for gene: KIF26A were set to Congenital brain malformations, no OMIM # Review for gene: KIF26A was set to GREEN Added comment: 5 unrelated patients with biallelic loss-of-function variants in KIF26A (found through WES), exhibiting a spectrum of congenital brain malformations (schizencephaly, corpus callosum anomalies, polymicrgyria, and ventriculomegaly). Combining mice and human iPSC-derived organoid models, they discovered that loss of KIF26A causes excitatory neuron-specific defects in radial migration, localization, dendritic and axonal growth, and apoptosis, offering a convincing explanation of the disease etiology in patients. Single-cell RNA sequencing in KIF26A knockout organoids revealed transcriptional changes in MAPK, MYC, and E2F pathways. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.4915 | COX11 |
Chern Lim gene: COX11 was added gene: COX11 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: COX11 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: COX11 were set to 36030551 Phenotypes for gene: COX11 were set to Mitochondrial disease (MONDO:0044970), COX11-related Review for gene: COX11 was set to GREEN gene: COX11 was marked as current diagnostic Added comment: PMID: 36030551 - Biallelic variants in COX11 associated with infantile-onset mitochondrial encephalopathies in two unrelated consanguineous families, one with homozygous missense variant, another with homozygous frameshift variant. - Functional studies supported pathogenicity of the missense variant, and showed that mutant COX11 fibroblasts had decreased ATP levels which could be rescued by CoQ10. - RNA studies suggested the mutant transcript with p.(Val12Glyfs*21) is not degraded by nonsense mediated decay. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.4895 | ZMYND8 |
Konstantinos Varvagiannis gene: ZMYND8 was added gene: ZMYND8 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ZMYND8 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: ZMYND8 were set to 35916866; 32530565 Phenotypes for gene: ZMYND8 were set to Delayed speech and language development; Motor delay; Intellectual disability; Abnormality of cardiovascular system morphology; Hearing abnormality; Abnormality of vision; Abnormality of the face; Seizures Penetrance for gene: ZMYND8 were set to unknown Review for gene: ZMYND8 was set to GREEN Added comment: Dias et al (2022 - PMID: 35916866) describe the phenotype of 11 unrelated individuals with monoallelic de novo (or suspected de novo) missense (N=9) or truncating (N=2) ZMYND8 variants. One of these subjects was previously reported by Suzuki et al (2020 - PMID: 32530565). Features included speech delay/language difficulties (9/11), motor delay (9/11), ID (in 10/11 - profound in 1, moderate in 2), CHD (7/11 - PDA, VSD, ASD, pulmonary stenosis, etc), hearing or vision impairment (7/11). Seizures were reported in few (in text 5/11, table 2/11). Variable non-familial facial features were present in (9/11). As the authors discuss, ZMYND8 encodes a multidomain protein playing a role in transcription regulation, chromatin remodeling, regulation of super enhancers, DNA damage response/tumor suppression. The protein is broadly expressed in brain and shows highest expression in early development. Molecular modeling and/or a yeast two-hybrid system were suggestive of disrupted interaction of ZMYND8 with Drebrin (missense variants in PWWP domain) or GATAD2A (variants in MYND domain). Neuronal Zmynd8 knockdown in Drosophila resulted in deficits in habituation learning. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.4654 | VPS16 |
Ain Roesley gene: VPS16 was added gene: VPS16 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: VPS16 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: VPS16 were set to 33938619; 34013567; 34901436 Phenotypes for gene: VPS16 were set to mucopolysaccharidosis-like disorder, VPS16-related MONDO#0100365 Review for gene: VPS16 was set to GREEN gene: VPS16 was marked as current diagnostic Added comment: for AR MPS - developmental delay reported 3 unrelated families - 2x hom c.2272‐18C>A and 1x hom p.Trp180Cys RNA and functional studies done on the splice variant also associated with AD dystonia PMID:34901436 suggests dystonia is transcript specific Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.4495 | THUMPD1 |
Chern Lim changed review comment from: Broly, M. et al. (2022) manuscript accepted in AJHG: - 13 individuals from 8 families, loss of function variants (PTVs, one missense, one single AA del). - Common phenotypic findings included global developmental delay, speech delay, moderate to severe intellectual deficiency, behavioral abnormalities such as angry outbursts, facial dysmorphism and ophthalmological abnormalities. Sources: Other; to: Broly, M. et al. (2022), AJHG: - 13 individuals from 8 families, loss of function variants (PTVs, one missense, one single AA del). - Common phenotypic findings included global developmental delay, speech delay, moderate to severe intellectual deficiency, behavioral abnormalities such as angry outbursts, facial dysmorphism and ophthalmological abnormalities. Sources: Other |
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| Intellectual disability syndromic and non-syndromic v0.4495 | THUMPD1 |
Chern Lim gene: THUMPD1 was added gene: THUMPD1 was added to Intellectual disability syndromic and non-syndromic. Sources: Other Mode of inheritance for gene: THUMPD1 was set to BIALLELIC, autosomal or pseudoautosomal Phenotypes for gene: THUMPD1 were set to Syndromic form of intellectual disability associated with developmental delay, behavioral abnormalities, hearing loss and facial dysmorphism, AR gene: THUMPD1 was marked as current diagnostic Added comment: Broly, M. et al. (2022) manuscript accepted in AJHG: - 13 individuals from 8 families, loss of function variants (PTVs, one missense, one single AA del). - Common phenotypic findings included global developmental delay, speech delay, moderate to severe intellectual deficiency, behavioral abnormalities such as angry outbursts, facial dysmorphism and ophthalmological abnormalities. Sources: Other |
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| 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 v0.4051 | 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 |
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| Intellectual disability syndromic and non-syndromic v0.4040 | PIDD1 |
Konstantinos Varvagiannis gene: PIDD1 was added gene: PIDD1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: PIDD1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PIDD1 were set to 28397838; 29302074; 33414379; 34163010 Phenotypes for gene: PIDD1 were set to Global developmental delay; Intellectual disability; Seizures; Autism; Behavioral abnormality; Psychosis; Pachygyria; Lissencephaly; Abnormality of the corpus callosum Penetrance for gene: PIDD1 were set to Complete Review for gene: PIDD1 was set to GREEN Added comment: There is enough evidence to include this gene in the current panel with green rating. Biallelic PIDD1 pathogenic variants have been reported in 26 individuals (11 families) with DD (all), variable degrees of ID (mild to severe), behavioral (eg. aggression/self-mutilation in several, ADHD) and/or psychiatric abnormalities (ASD, psychosis in 5 belonging to 3 families), well-controlled epilepsy is some (9 subjects from 6 families) and MRI abnormalities notably abnormal gyration pattern (pachygyria with predominant anterior gradient) as well as corpus callosum anomalies (commonly thinning) in several. Dysmorphic features have been reported in almost all, although there has been no specific feature suggested. The first reports on the phenotype associated with biallelic PIDD1 mutations were made by Harripaul et al (2018 - PMID: 28397838) and Hu et al (2019 - PMID: 29302074) [both studies investigating large cohorts of individuals with ID from consanguineous families]. Sheikh et al (2021 - PMID: 33414379) provided details on the phenotype of 15 individuals from 5 families including those from the previous 2 reports and studied provided evidence on the role of PIDD1 and the effect of variants. Zaki et al (2021 - PMID: 34163010) reported 11 additional individuals from 6 consanguineous families, summarize the features of all subjects published in the literature and review the neuroradiological features of the disorder. PIDD1 encodes p53-induced death domain protein 1. The protein is part of the PIDDosome, a multiprotein complex also composed of the bipartite linker protein CRADD (also known as RAIDD) and the proform of caspase-2 and induces apoptosis in response to DNA damage. There are 5 potential PIDD1 mRNA transcript variants with NM_145886.4 corresponding to the longest. Similar to the protein encoded by CRADD, PIDD1 contains a death domain (DD - aa 774-893). Constitutive post-translational processing gives PIDD1-N, PIDD1-C the latter further processed into PIDD1-CC (by auto-cleavage). Serine residues at pos. 446 and 588 are involved in this autoprocessing generating PIDD1-C (aa 446-910) and PIDD1-CC (aa 774-893). The latter is needed for caspase-2 activation. Most (if not all) individuals belonged to consanguineous families of different origins and harbored pLoF or missense variants. Variants reported so far include : c.2587C>T; p.Gln863* / c.1909C>T ; p.Arg637* / c.2443C>T / p.Arg815Trp / c.2275-1G>A which upon trap assay was shown to lead to skipping of ex15 with direct splicing form exon14 to the terminal exon 16 (resulting to p.Arg759Glyfs*1 with exlcusion of the entire DD) / c.2584C>T; p.Arg862Trp / c.1340G>A; p.Trp447* / c.2116_2120del; p.Val706His*, c.1564_1565del; p.Gly602fs*26 Evidence so far provided includes: - Biallelic CRADD variants cause a NDD disorder and a highly similar gyration pattern. - Confirmation of splicing effect (eg. for c.2275-1G>A premature stop in position 760) or poor expression (NM_145886.3:c.2587C>T; p.Gln863*). Arg815Trp did not affect autoprocessing or protein stability. - Abnormal localization pattern, loss of interaction with CRADD and failure to activate caspase-2 (MDM2 cleavage assay) [p.Gln863* and Arg815Trp] - Available expression data from GTEx (PIDD1 having broad expression in multiple tissues, but higher in brain cerebellum) as well as BrainSpan and PsychEncode studies suggesting high coexpression of PIDD1, CRADD and CASP2 in many regions in the developing human brain. - Variants in other genes encoding proteins interacting with PIDD1 (MADD, FADD, DNAJ, etc) are associated with NDD. Pidd-1 ko mice (ex3-15 removal) lack however CNS-related phenotypes. These show decreased anxiety but no motor anomalies. This has also been the case with Cradd-/- mice displaying no significant CNS phenotypes without lamination defects. There is currently no associated phenotype in OMIM, PanelApp Australia. PIDD1 is listed in the DD panel of G2P (PIDD1-related NDD / biallelic / loss of function / probable) . SysID includes PIDD1 among the current primary ID genes. Overall the gene appears to be relevant for the epilepsy panel, panels for gyration and/or corpus callosum anomalies etc. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3864 | RFX4 |
Chirag Patel gene: RFX4 was added gene: RFX4 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: RFX4 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: RFX4 were set to PMID: 33658631 Phenotypes for gene: RFX4 were set to ID, ASD, ADHD Review for gene: RFX4 was set to GREEN Added comment: Report of 38 individuals (from 33 unrelated families) with de novo or inherited loss of function variants in RFX3 (15 families), RFX4 (4 families), and RFX7 (14 families), identified through WES. Individuals share neurobehavioural features including ASD, intellectual disability, and/or ADHD; other frequent features include hypersensitivity to sensory stimuli and sleep problems. RFX3, RFX4, and RFX7 are strongly expressed in developing and adult human brain, and X-box binding motifs as well as RFX ChIP-seq peaks are enriched in the cis-regulatory regions of known ASD risk genes. These genes are potentially critical transcriptional regulators of neurobiological pathways associated with neurodevelopmental disease pathogenesis. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3864 | RFX3 |
Chirag Patel gene: RFX3 was added gene: RFX3 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: RFX3 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: RFX3 were set to PMID: 33658631 Phenotypes for gene: RFX3 were set to ID, ASD, ADHD Review for gene: RFX3 was set to GREEN Added comment: Report of 38 individuals (from 33 unrelated families) with de novo or inherited loss of function variants in RFX3 (15 families), RFX4 (4 families), and RFX7 (14 families), identified through WES. Individuals share neurobehavioural features including ASD, intellectual disability, and/or ADHD; other frequent features include hypersensitivity to sensory stimuli and sleep problems. RFX3, RFX4, and RFX7 are strongly expressed in developing and adult human brain, and X-box binding motifs as well as RFX ChIP-seq peaks are enriched in the cis-regulatory regions of known ASD risk genes. These genes are potentially critical transcriptional regulators of neurobiological pathways associated with neurodevelopmental disease pathogenesis. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3864 | RFX7 |
Chirag Patel gene: RFX7 was added gene: RFX7 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: RFX7 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: RFX7 were set to PMID: 33658631 Phenotypes for gene: RFX7 were set to ID, ASD, ADHD Review for gene: RFX7 was set to GREEN Added comment: Report of 38 individuals (from 33 unrelated families) with de novo or inherited loss of function variants in RFX3 (15 families), RFX4 (4 families), and RFX7 (14 families), identified through WES. Individuals share neurobehavioural features including ASD, intellectual disability, and/or ADHD; other frequent features include hypersensitivity to sensory stimuli and sleep problems. RFX3, RFX4, and RFX7 are strongly expressed in developing and adult human brain, and X-box binding motifs as well as RFX ChIP-seq peaks are enriched in the cis-regulatory regions of known ASD risk genes. These genes are potentially critical transcriptional regulators of neurobiological pathways associated with neurodevelopmental disease pathogenesis. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3452 | MSL3 | Zornitza Stark commented on gene: MSL3: Well established ID gene. 2021 paper documents findings in 25 individuals. Variants found to be clustering in the terminal eight exons suggesting that truncating variants in the first five exons might be compensated by an alternative MSL3 transcript. Three-dimensional modeling of missense and splice variants indicated that these have a deleterious effect. The main clinical findings comprised developmental delay and intellectual disability ranging from mild to severe. Autism spectrum disorder, muscle tone abnormalities, and macrocephaly were common as well as hearing impairment and gastrointestinal problems. Hypoplasia of the cerebellar vermis emerged as a consistent magnetic resonance image (MRI) finding. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3128 | PRKAR1B |
Konstantinos Varvagiannis gene: PRKAR1B was added gene: PRKAR1B was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: PRKAR1B was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: PRKAR1B were set to https://doi.org/10.1101/2020.09.10.20190314; 33057194 Phenotypes for gene: PRKAR1B were set to Global developmental delay; Intellectual disability; Autism; Attention deficit hyperactivity disorder; Aggressive behavior; Abnormality of movement; Upslanted palpebral fissure Penetrance for gene: PRKAR1B were set to unknown Review for gene: PRKAR1B was set to AMBER Added comment: Please consider inclusion of this gene with amber rating pending publication of the preprint and/or additional evidence. Marbach et al. (2020 - medRxiv : https://doi.org/10.1101/2020.09.10.20190314 - last author : C. Schaaf) report 6 unrelated individuals with heterozygous missense PRKAR1B variants. All presented formal ASD diagnosis (6/6), global developmental delay (6/6) and intellectual disability (all - formal evaluations were lacking though). Additional features included neurologic anomalies (movement disorders : dyspraxia, apraxia, clumsiness in all, with tremor/dystonia or involuntary movements as single occurrences). Three displayed high pain tolerance. Regression in speech was a feature in two. Additional behavior anomalies included ADHD (4-5/6) or aggression (3/6). There was no consistent pattern of malformations, physical anomalies or facial features (with the exception of uplsanted palpebral fissures reported in 4). 3 different missense variants were identified (NM_00116470:c.1003C>T - p.Arg335Trp, c.586G>A - p.Glu196Lys, c.500_501delAAinsTT - p.Gln167Leu) with Arg355Trp being a recurrent one within this cohort (4/6 subjects). A possible splicing effect may apply for the MNV. All variants are absent from gnomAD and the SNVs had CADD scores > 24. In all cases were parental samples were available (5/6), the variant had occurred as a de novo event. 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. As the authors comment, the RIβ subunit is primarily expressed in brain with higher expression in cortex and hypothalamus. The functional consequences of the variants at cellular level were not studied. Previous studies have demonstrated that downregulation of RIβ in murine hippocampal cultures, reduced phosphorylation of CREB, a transcription factor involved in long-term memory formation. The authors speculate that a similar effect on cAMP/PKA/CREB cascade may mediate the cognitive effects in humans. RIβ deficient mice also display diminished nociceptive pain, similar to the human phenotype. [Several refs provided]. The authors cite the study by Kaplanis et al (2020 - PMID: 33057194), where in a large sample of 31,058 trio exomes of children with developmental disorders, PRKAR1B was among the genes with significant enrichment for de novo missense variants. [The gene has a pLI score of 0.18 in gnomAD / o/e = 0.26 - so pLoF variants may not be deleterious]. Please note that a specific PRKAR1B variant (NM_002735.2:c.149T>G - p.Leu50Arg) has been previous reported to segregate with a late-onset neurodegenerative disorder characterized by dementia and/or parkinsonism within a large pedigree with 12 affected individuals [Wong et al 2014 - PMID: 25414040]. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3013 | ZMYM2 |
Konstantinos Varvagiannis gene: ZMYM2 was added gene: ZMYM2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ZMYM2 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: ZMYM2 were set to 32891193 Phenotypes for gene: ZMYM2 were set to Abnormality of the urinary system; Global developmental delay; Intellectual disability; Microcephaly; Abnormality of the cardiovascular system; Autism; Seizures; Abnormality of the head or neck; Abnormality of the nail; Small hand; Short foot; Clinodactyly Penetrance for gene: ZMYM2 were set to unknown Review for gene: ZMYM2 was set to AMBER Added comment: Heterozygous pathogenic (pLoF) ZMYM2 variants have been reported in individuals with syndromic presentation including CAKUT (in several cases) and variable neurological manifestations among extra-renal features. DD and ID were reported in some of the families described to date as summarized below. You might consider inclusion with green/amber rating in the ID panel and green in the panel for CAKUT. -- Connaughton et al (2020 - PMID: 32891193) report on 19 individuals (from 15 unrelated families) with heterozygous pathogenic ZMYM2 variants. [Article not reviewed in detail]. Affected individuals from 7 families presented with CAKUT while all of them displayed extra-renal features. Neurological manifestations were reported in 16 individuals from 14 families (data not available for 1 fam), among others hypotonia (3/14 fam), speech delay (4/14 fam), global DD (9/14 fam), ID (4/14 fam), microcephaly (4/14 fam). ASD was reported in 4 fam (4 indiv). Seizures were reported in 2 fam (2 indiv). Variable other features included cardiac defects, facial dysmorphisms, small hands and feet with dys-/hypo-plastic nails and clinodactyly. 14 pLoF variants were identified, in most cases as de novo events (8 fam). In 2 families the variant was inherited from an affected parent. Germline mosaicism occurred in 1 family. The human disease features were recapitulated in a X. tropicalis morpholino knockdown, with expression of truncating variants failing to rescue renal and craniofacial defects. Heterozygous Zmym2-deficient mice also recapitulated the features of CAKUT. ZMYM2 (previously ZNF198) encodes a nuclear zinc finger protein localizing to the nucleus (and PML nuclear body). It has previously been identified as transcriptional corepressor interacting with nuclear receptors and the LSD1-CoREST-HDAC1 complex. It has also been shown to interact with FOXP transcription factors. The authors provide evidence for loss of interaction of the truncated ZMYM2 with FOXP1 (mutations in the latter having recently been reported in syndromic CAKUT). Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.2920 | CTNND1 |
Zornitza Stark gene: CTNND1 was added gene: CTNND1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: CTNND1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: CTNND1 were set to 28301459; 32196547 Phenotypes for gene: CTNND1 were set to Blepharocheilodontic syndrome 2, MIM# 617681 Review for gene: CTNND1 was set to AMBER Added comment: 4 individuals from 3 unrelated families with blepharocheilodontic syndrome and mutations in the CTNND1 gene reported originally in PMID 28301459. All had eyelid anomalies, including ectropion of the lower lids, euryblepharon, lagophthalmia, and distichiasis. In addition, all 4 showed typical facial dysmorphism with hypertelorism, flat face, and high forehead, and all had conical teeth and tooth agenesis. Three had cleft lip and palate, 3 had hair anomalies, and 1 had hypothyroidism due to hypoplasia or aplasia of the thyroid gland. None of the patients exhibited anal atresia or neural tube defects. PMID: 32196547 - Alharatani et al 2020 - report an expanded phenotype for CTNND1 patients. They report 13 individuals from nine families with novel protein-truncating variants in CTNND1 identified by WES. The mutations were not previously described in blepharocheilodontic (BCD), orofacial cleft cases nor in gnomAD. 8 patients had de novo variants, 2 inherited from affected parents, 2 participants inherited a variant from a parent with a mild phenotype. 8/13 patients showed cleft palate. Additional phenotypic features seen include mild limb phenotypes (9/13), cardiovascular anomalies (6/13) and Developmental delay and other neurodevelopmental problems (8/13). This more recent publication suggests a broader phenotype associated with CTNND1 variants including dev delay, ADHD/ASD, behavioural issues. Unclear from description whether significant ID present. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.2836 | TAF1C |
Konstantinos Varvagiannis gene: TAF1C was added gene: TAF1C was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: TAF1C was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: TAF1C were set to 32779182 Phenotypes for gene: TAF1C were set to Global developmental delay; Intellectual disability; Spasticity; Strabismus; Seizures; Abnormality of nervous system morphology Penetrance for gene: TAF1C were set to Complete Review for gene: TAF1C was set to AMBER Added comment: Knuutinen et al (2020 - PMID: 32779182) report on 2 individuals from 2 consanguineous families, homozygous for TAF1C missense variants. Both presented with an early onset neurological phenotype with severe global DD, ID (2/2 - moderate and profound), spasticity (2/2), ophthalmic findings (strabismus 2/2, nystagmus 1/2). Epilepsy, abnormal brain MRI (cerebral and cerebellar atrophy and white matter hyperintensities) as well and additional findings were reported in one (always the same individual). Following a normal CMA, exome in the first case revealed a homozygous missense SNV (NM_005679.3:c.1165C>T / p.Arg389Cys) supported by in silico predictions. mRNA and protein levels were substantially reduced in fibroblasts from this subject. Only the patient and parents were tested for the variant but not 3 unaffected sibs (fig1). The second individual was homozygous for another missense variant (p.Arg405Cys) also supported by in silico predictions. The girl was the single affected person within the family with an unaffected sib and parents heterozygous for the variant. Several other unaffected relatives in the extended pedigree were either carriers for this variant or homozygous for the wt allele. TAF1C encodes the TATA-box binding protein associated factor (TAF) RNA polymerase I subunit. RNA polymerase I (Pol I) transcribes genes to produce rRNA. For Pol I to initiate transcription, two transcription factors are required : UBF (upstream binding factor encoded by UBTF) and SL1 (selectivity factor 1). The latter is formed by TBP (TATA-binding protein) and 3 Pol I-specific TBP-associated factors (TAFs). A recurrent de novo missense variant in UBTF (encoding the other Pol I transcription factor) causes a disorder with highly similar features. The specific variant acts through a gain-of-function mechanism (and not by LoF which appears to apply for TAF1C based on expression data). The authors hypothesize that altered Pol I activity and resulting ribosomal stress could cause the microcephaly and leukodystrophy (both reported in 1 - the same - individual). As a result, TAF1C may be considered for inclusion in the ID panel with amber rating pending further evidence. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.2833 | FAM50A |
Konstantinos Varvagiannis gene: FAM50A was added gene: FAM50A was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: FAM50A was set to X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males) Publications for gene: FAM50A were set to 32703943 Phenotypes for gene: FAM50A were set to Mental retardation syndrome, X-linked, Armfield type (MIM #300261) Penetrance for gene: FAM50A were set to unknown Review for gene: FAM50A was set to GREEN Added comment: Lee et al (2020 - PMID: 32703943) provide evidence that Armfield X-Linked intellectual disability syndrome is caused by monoallelic FAM50A pathogenic variants. The current review is based only on this reference. The authors provide clinical details on 6 affected individuals from 5 families. Features included postnatal growth delay, DD and ID (6/6 - also evident for those without formal IQ assesment), seizures (3/6 from 2 families), prominent forehead with presence of other facial features and variable head circumference (5th to >97th %le), ocular anomalies (5/6 - strabismus/nystagmus/Axenfeld-Rieger), cardiac (3/6 - ASD/Fallot) and genitourinary anomalies (3/6). In the first of these families (Armfield et al 1999 - PMID: 10398235), linkage analysis followed by additional studies (Sanger, NGS of 718 genes on chrX, X-exome NGS - several refs provided) allowed the identification of a FAM50A variant. Variants in other families were identified by singleton (1 fam) or trio-ES (3 fam). In affected individuals from 3 families, the variant had occurred de novo. Carrier females in the other families were unaffected (based on pedigrees and/or the original publication). XCI was rather biased in most obligate carrier females from the 1st family (although this ranged from 95:5 to 60:40). Missense variants were reported in all affected subjects incl. Trp206Gly, Asp255Gly, Asp255Asn (dn), Glu254Gly (dn), Arg273Trp (dn) (NM_004699.3). Previous studies have demonstrated that FAM50A has ubiquitous expression in human fetal and adult tissues (incl. brain in fetal ones). Immunostaining suggests a nuclear localization for the protein (NIH/3T3 cells). Comparison of protein levels in LCLs from affected males and controls did not demonstrate significant differences. Protein localization for 3 variants (transfection of COS-7 cells) was shown to be similar to wt. Complementation studies in zebrafish provided evidence that the identified variants confer partial loss of function (rescue of the morpholino phenotype with co-injection of wt but not mt mRNA). The zebrafish ko model seemed to recapitulate the abnormal development of cephalic structures and was indicative of diminished/defective neurogenesis. Transcriptional dysregulation was demonstrated in zebrafish (altered levels and mis-splicing). Upregulation of spliceosome effectors was demonstrated in ko zebrafish. Similarly, mRNA expression and splicing defects were demonstrated in LCLs from affected individuals. FAM50A pulldown followed by mass spectrometry in transfected HEK293T cells demonstrated enrichment of binding proteins involved in RNA processing and co-immunoprecipitation assays (transfected U-87 cells) suggested that FAM50A interacts with spliceosome U5 and C-complex proteins. Overall aberrant spliceosome C-complex function is suggested as the underlying pathogenetic mechanism. Several other neurodevelopmental syndromes are caused by variants in genes encoding C-complex affiliated proteins (incl. EFTUD2, EIF4A3, THOC2, etc.). Please consider inclusion in the ID panel with green rating and epilepsy panel with amber (seizures in individuals from 2 families). Sources: Literature |
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| 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 |
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| Intellectual disability syndromic and non-syndromic v0.2783 | MORC2 |
Konstantinos Varvagiannis gene: MORC2 was added gene: MORC2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: MORC2 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: MORC2 were set to https://doi.org/10.1016/j.ajhg.2020.06.013 Phenotypes for gene: MORC2 were set to Charcot-Marie-Tooth disease, axonal, type 2Z, MIM #616688 Penetrance for gene: MORC2 were set to unknown Mode of pathogenicity for gene: MORC2 was set to Loss-of-function variants (as defined in pop up message) DO NOT cause this phenotype - please provide details in the comments Review for gene: MORC2 was set to GREEN Added comment: The current review is based on a recent report by Sacoto et al (2020 - https://doi.org/10.1016/j.ajhg.2020.06.013). While several previous studies focused on the phenotype of axonal motor and senory neuropathy in individuals with heterozygous MORC2 pathogenic variants (Charcot-Marie-Tooth disease, axonal, type 2Z, MIM #616688) some of them presented among others with hypotonia, muscle weakness, intellectual disability, microcephaly or hearing loss [refs provided by Sacoto et al - learning disabilities (in some patients) also listed in OMIM's clinical synopsis]. Sacoto et al present a cohort of 20 individuals having genetic testing for developmental delay or growth failure (with a single one for a diagnosis of sensorimotor neuropathy). Overlapping features included DD, ID (18/20 - mild to severe), short stature (18/20), microcephaly (15/20) and variable craniofacial dysmorphisms. The authors comment that features suggestive of neuropathy (weakness, hyporeflexia, abnormal EMG/NCS) were frequent but not the predominant complaint. EMG/NCS abnormalities were abnormal in 6 out of 10 subjects investigated in this cohort. Other findings included brain MRI abnormalities (12/18 - in 5/18 Leigh-like lesions), hearing loss (11/19) and pigmentary retinopathy in few (5). Affected subjects were found to harbor in all cases missense variants in the ATPase module of MORC2 [residues 1 to 494 - NM_001303256.1 - the module consists of an ATPase domain (aa 1-265), a transducer S5-like domain (266-494) and a coiled-coiled domain (CC1 - aa 282-361)]. Variants had occured mostly as de novo events although inheritance from a similarly affected parent was also reported. Some of them were recurring within this cohort and/or the literature eg. c.79G>A/p.Glu27Lys (x5), c.260C>T/p.Ser87Leu (x2), c.394C>T/p.Arg132Cys (4x), c.1164C>G/p.Ser388Arg (x2), c.1181A>G/p.Tyr394Cys (x3). MORC2 encodes an ATPase involved in chromatin remodeling, DNA repair and transcriptional regulation. Chromatin remodeling and epigenetic silencing by MORC2 is mediated by the HUSH (Human Silencing Hub) complex. Functional studies (MORC2-knockout HeLa cells harboring a HUSH-sensitive GFP reporter were transduced with wt or mt MORC2 followed by measurement of reporter repression) supported the deleterious effect of most variants known at the time (hyperactivation of HUSH-mediating silencing, in line with previous observations). Overall this gene can be considered for inclusion in the ID panel with green rating. Also other gene panels (e.g. for short stature, microcephaly, hearing loss, pigmentary retinopathy, etc) if it meets the respective criteria for inclusion. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.2750 | PAX1 |
Konstantinos Varvagiannis gene: PAX1 was added gene: PAX1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature,Radboud University Medical Center, Nijmegen Mode of inheritance for gene: PAX1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PAX1 were set to 29681087; 23851939; 28657137 Phenotypes for gene: PAX1 were set to Otofaciocervical syndrome 2, 615560 Penetrance for gene: PAX1 were set to Complete Review for gene: PAX1 was set to AMBER Added comment: Biallelic PAX1 pathogenic variants cause Otofaciocervical syndrome 2 (OMIM 615560). Brief review of the literature suggests 3 relevant publications to date (04-07-2020). 2 individuals with DD and ID have been reported (Patil et al, 2018 - PMID: 29681087 and Pohl et al, 2013 - PMID: 23851939). Other subjects reported were only evaluated as newborns(mostly)/infants [Paganini et al, 2017 - PMID: 28657137, Patil et al, 2018 - PMID: 29681087]. While the first report by Pohl et al identified a homozygous missense variant supported by functional studies [NM_006192.5:c.497G>T - p.(Gly166Val)] subsequent ones identified homozygosity for pLoF mutations [Patil et al: NM_006192.4:c.1173_1174insGCCCG / Paganini et al: NM_006192:c.1104C>A - p.(Cys368*)]. As discussed by Pohl et al: PAX1 encodes a transcription factor with critical role in pattern formation during embryogenesis. Study of the mouse Gly157Val (equivalent to human Gly166Val) Pax1 variant suggested reduced binding affinity (reduced transactivation of a regulatory sequence of the Nkx3-2 promoter) and hypofunctional nature of this variant. Mouse models seem to recapitulate features of the disorder (skeletal, immunodeficiency) while the role of Pax1 in hearing process was thought to be supported by early expression (P6) in mouse cochlea. Overall this gene can be considered for inclusion in the ID panel with amber/green rating. Sources: Literature, Radboud University Medical Center, Nijmegen |
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| Intellectual disability syndromic and non-syndromic v0.2665 | DSCR3 |
Chirag Patel gene: DSCR3 was added gene: DSCR3 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: DSCR3 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: DSCR3 were set to PMID: 31845315 Phenotypes for gene: DSCR3 were set to Intellectual disability, no OMIM # yet Review for gene: DSCR3 was set to RED Added comment: 1 family/2 cousins with cognitive impairment, growth failure, skeletal abnormalities, and distinctive facial features. Both shared the homozygous nonsense variant c.178G>T (p.Glu60*) in the VPS26C gene. This gene encodes VPS26C, a member of the retriever integral membrane protein recycling pathway. The nature of the variant which is predicted to result in loss‐of‐function, expression studies revealing significant reduction in the mutant transcript, and the co‐segregation of the homozygous variant with the phenotype in two affected individuals. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.2377 | NDUFA10 | Zornitza Stark edited their review of gene: NDUFA10: Added comment: Two families, functional data, but phenotypic description only available for one (DD/ID part of the phenotype).; Changed rating: AMBER | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2237 | RAX |
Sebastian Lunke gene: RAX was added gene: RAX was added to Intellectual disability syndromic and non-syndromic. Sources: Expert Review Mode of inheritance for gene: RAX was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: RAX were set to 30762128; 24033328 Phenotypes for gene: RAX were set to MICROPHTHALMIA, ISOLATED 3; MCOP3 Review for gene: RAX was set to RED Added comment: Only three cases described with intellectual disability in addition to microphthalmia, no new descriptions of ID association since 2014. Not clear if the cases are from the same or different families. Link with ID seems tenuous at best. Sources: Expert Review |
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| Intellectual disability syndromic and non-syndromic v0.2117 | ZIC1 |
Chirag Patel gene: ZIC1 was added gene: ZIC1 was added to Intellectual disability syndromic and non-syndromic. Sources: Expert list Mode of inheritance for gene: ZIC1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: ZIC1 were set to PMID: 26340333, 30391508 Phenotypes for gene: ZIC1 were set to Structural brain anomalies with impaired intellectual development and craniosynostosis; OMIM #618736 Review for gene: ZIC1 was set to GREEN Added comment: 5 families with heterozygous mutations located in the final (third) exon of ZIC1 who have a distinct phenotype in which severe craniosynostosis, specifically involving the coronal sutures, and variable learning disability are the most characteristic features. The location of the nonsense mutations predicts escape of mutant ZIC1 transcripts from nonsense-mediated decay, which was confirmed in a cell line from an affected individual. Both nonsense and missense mutations are associated with altered and/or enhanced expression of a target gene, engrailed-2, in a Xenopus embryo assay. Analysis of mouse embryos revealed a localized domain of Zic1 expression at embryonic days 11.5-12.5 in a region overlapping the supraorbital regulatory center, which patterns the coronal suture. 2 sibs with BAIDCS, Vandervore et al. (2018) identified heterozygosity for a frameshift mutation in the ZIC1 gene. Neither parent had evidence of the mutation by whole-exome sequencing, suggesting that gonadal mosaicism for the mutation was present in one of the parents. Expression of the mutated allele was detected in patient fibroblasts by RT-PCR, evidence that the mutant mRNA did not undergo nonsense-mediated decay and probably generates an abnormal protein. Also heterozygous deletions of ZIC1 on chromosome 3q25.1 are associated with Dandy-Walker malformation of the cerebellum. Loss of the orthologous Zic1 gene in the mouse causes cerebellar hypoplasia and vertebral defects. Sources: Expert list |
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| Intellectual disability syndromic and non-syndromic v0.1402 | ZMIZ1 | Zornitza Stark Added comment: Comment when marking as ready: Please note transcription error in review relating to another gene, ZNF292. 19 families reported with heterozygous variants in this gene and a neurodevelopmental phenotype. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1349 | GTF2E2 |
Chirag Patel changed review comment from: 2 unrelated non-photosensitive TTD families with homozygous missense mutation in GTF2E2. Functional evidence showing mutant TFIIEβ strongly reduces the total amount of the entire TFIIE complex, with a remarkable temperature-sensitive transcription defect, which strikingly correlates with the phenotypic aggravation of key clinical symptoms after episodes of high fever. Induced pluripotent stem cell reprogramming of patient fibroblasts followed by in vitro erythroid differentiation, showed a clear hematopoietic defect during late-stage differentiation associated with hemoglobin subunit imbalance. Sources: Literature; to: 2 unrelated non-photosensitive TTD families (3 affected) with homozygous missense mutation in GTF2E2. Functional evidence showing mutant TFIIEβ strongly reduces the total amount of the entire TFIIE complex, with a remarkable temperature-sensitive transcription defect, which strikingly correlates with the phenotypic aggravation of key clinical symptoms after episodes of high fever. Induced pluripotent stem cell reprogramming of patient fibroblasts followed by in vitro erythroid differentiation, showed a clear hematopoietic defect during late-stage differentiation associated with hemoglobin subunit imbalance. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.1348 | GTF2E2 |
Chirag Patel gene: GTF2E2 was added gene: GTF2E2 was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: GTF2E2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: GTF2E2 were set to PMID: 28973399 Phenotypes for gene: GTF2E2 were set to Trichothiodystrophy 6, nonphotosensitive; OMIM #616943 Review for gene: GTF2E2 was set to AMBER Added comment: 2 unrelated non-photosensitive TTD families with homozygous missense mutation in GTF2E2. Functional evidence showing mutant TFIIEβ strongly reduces the total amount of the entire TFIIE complex, with a remarkable temperature-sensitive transcription defect, which strikingly correlates with the phenotypic aggravation of key clinical symptoms after episodes of high fever. Induced pluripotent stem cell reprogramming of patient fibroblasts followed by in vitro erythroid differentiation, showed a clear hematopoietic defect during late-stage differentiation associated with hemoglobin subunit imbalance. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.1337 | MEPCE |
Chirag Patel gene: MEPCE was added gene: MEPCE was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: MEPCE was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: MEPCE were set to PMID: 31467394 Phenotypes for gene: MEPCE were set to no OMIM number yet Review for gene: MEPCE was set to RED Added comment: 1 patient with global DD and seizures with de novo MEPCE nonsense variant. mRNA and protein analyses identified nonsense-mediated mRNA decay to underlie the decreased amount of MEPCE in patient fibroblasts followed by LARP7 and 7SK snRNA downregulation and HEXIM1 upregulation. Flavopiridol treatment and ectopic MEPCE protein expression in patient fibroblasts rescued increased expression of six RNAP II-sensitive genes and suggested a possible repressive effect of MEPCE on P-TEFb-dependent transcription of specific genes. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.1326 | PHF21A |
Chirag Patel gene: PHF21A was added gene: PHF21A was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: PHF21A was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: PHF21A were set to PMID: 31649809; 30487643; 22770980 Phenotypes for gene: PHF21A were set to no OMIM number yet. Review for gene: PHF21A was set to GREEN Added comment: 9 cases with intellectual disability and craniofacial anomalies (Potocki-Shaffer syndrome), with de novo truncating variants in PHF21A. No functional evidence of variants, but PHF21A is highly expressed in the human fetal brain, which is consistent with the neurodevelopmental phenotype. 2 other unrelated individuals with translocations disrupting PHF21A. Lymphoblastoid cell lines from translocation subjects showed derepression of the neuronal gene SCN3A and reduced LSD1 occupancy at the SCN3A promoter, supporting a direct functional consequence of PHF21A haploinsufficiency on transcriptional regulation. Sources: Literature |
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| 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. |
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| 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 |
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| Intellectual disability syndromic and non-syndromic v0.1298 | SMARCC2 |
Chirag Patel gene: SMARCC2 was added gene: SMARCC2 was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: SMARCC2 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: SMARCC2 were set to PMID: 30580808 Phenotypes for gene: SMARCC2 were set to Coffin-Siris syndrome 8; OMIM #618362 Review for gene: SMARCC2 was set to GREEN Added comment: 15 individuals with variable degrees of neurodevelopmental delay, growth retardation, prominent speech impairment, hypotonia, feeding difficulties, behavioral abnormalities, and dysmorphic features. They found heterozygous de novo SMARCC2 variants, but no functional evidence of specific variants. Transcriptomic analysis of fibroblasts from affected individuals highlighted a group of differentially expressed genes with possible roles in regulation of neuronal development and function, namely H19, SCRG1, RELN, and CACNB4. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.1296 | SMARCD1 |
Chirag Patel gene: SMARCD1 was added gene: SMARCD1 was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: SMARCD1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: SMARCD1 were set to PMID: 30879640 Phenotypes for gene: SMARCD1 were set to no OMIM number yet Review for gene: SMARCD1 was set to GREEN Added comment: 5 individuals with heterozygous SMARCD1 variants (4 de novo, 1 unk), and developmental delay, intellectual disability, hypotonia, feeding difficulties, dysmorphisms, and small hands and feet. No functional evidence of some variants was not conclusive with immunoblot or co-immunoprecipitation studies. Targeted knockdown of Drosophila ortholog Bap60 in the mushroom body of adult flies causes defects in long-term memory. Mushroom-body-specific transcriptome analysis revealed that Bap60 is required for context-dependent expression of genes involved in neuron function and development in juvenile flies when synaptic connections are actively being formed in response to experience. T Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.798 | ADRA2B |
Zornitza Stark gene: ADRA2B was added gene: ADRA2B was added to Intellectual disability, syndromic and non-syndromic_GHQ. Sources: Expert list Mode of inheritance for gene: ADRA2B was set to BOTH monoallelic and biallelic, autosomal or pseudoautosomal Publications for gene: ADRA2B were set to 24114805; 21937992 Phenotypes for gene: ADRA2B were set to Cortical myoclonus and epilepsy; Intellectual disability Review for gene: ADRA2B was set to RED Added comment: Two families reported but same mutation, ?founder effect. Most affected individuals had normal intellect. Another paper linking to AR intellectual disability but as part of manuscript reporting multiple novel candidates. Sources: Expert list |
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| Intellectual disability syndromic and non-syndromic v0.302 | ZNF41 | Chirag Patel changed review comment from: Shoichet et al. (2003) described a female patient with severe nonsyndromic mental retardation and a de novo balanced translocation t(X;7)(p11.3;q11.21) in whom they cloned the DNA fragment that contained the X chromosomal and the autosomal breakpoint. In silico sequence analysis demonstrated that the ZNF41 gene was disrupted. Expression studies indicated that ZNF41 transcripts were absent in the patient cell line, suggesting that the mental disorder in this patient resulted from loss of functional ZNF41. Moreover, screening of a panel of patients with MRX led to the identification of 2 other ZNF41 mutations (314995.0001-314995.0002) that were not found in healthy control individuals. Based on their finding of the mutations in ZNF41 identified by Shoichet et al. (2003) in a total of 7 males in the NHLBI Exome Variant Server, and the additional finding of truncating ZNF41 variants in 1 male and 1 female in that database, Piton et al. (2013) classified the involvement of ZNF41 in mental retardation as highly questionable.; to: Shoichet et al. (2003) described a female patient with severe nonsyndromic mental retardation and a de novo balanced translocation t(X;7)(p11.3;q11.21) in whom they cloned the DNA fragment that contained the X chromosomal and the autosomal breakpoint. In silico sequence analysis demonstrated that the ZNF41 gene was disrupted. Expression studies indicated that ZNF41 transcripts were absent in the patient cell line, suggesting that the mental disorder in this patient resulted from loss of functional ZNF41. Screening of patients with mental retardation led to the identification of 2 other ZNF41 mutations that were not found in healthy control individuals. Based on their finding of the mutations in ZNF41 identified by Shoichet et al. (2003) in a total of 7 males in the NHLBI Exome Variant Server, and the additional finding of truncating ZNF41 variants in 1 male and 1 female in that database, Piton et al. (2013) classified the involvement of ZNF41 in mental retardation as highly questionable. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||