Activity

Filter

Cancel
Date Panel Item Activity
84 actions
Mendeliome v1.2015 EXOC3L2 Zornitza Stark Phenotypes for gene: EXOC3L2 were changed from Dandy-Walker malformation, MONDO:0009072; renal dysplasia; bone marrow failure to Brain malformation renal syndrome, MIM# 620943
Mendeliome v1.1998 GPN2 Mark Cleghorn gene: GPN2 was added
gene: GPN2 was added to Mendeliome. Sources: Other
Mode of inheritance for gene: GPN2 was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: GPN2 were set to complex neurodevelopmental disorder MONDO:0100038; Perrault syndrome
Penetrance for gene: GPN2 were set to unknown
Review for gene: GPN2 was set to AMBER
Added comment: GPN2
ESHG talk 2/6/24, unpublished
Thomas Smith, University of Manchester

Biallelic GPN2 proposed to cause Perrault syndrome (SNHL, ovarian dysfunction, NDD)
RNA polymerase assembly factor

4 families (14 affected individuals) w biallalic GPN2 rare missense variants
Segregated w phenotype
Fam 2 and 3 may be distantly related (leaving 3 distinct kindreds)

Clinical features
13/14 SNHL
3/4 families all females of adolescent age or older had primary ovarian insufficiency
4/4 GDD, ataxia (no data on family w 10 affected indiv.)

Some functional work, not conclusive
Sources: Other
Mendeliome v1.1980 MED22 Mark Cleghorn gene: MED22 was added
gene: MED22 was added to Mendeliome. Sources: Other
Mode of inheritance for gene: MED22 was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: MED22 were set to complex neurodevelopmental disorder MONDO:0100038
Penetrance for gene: MED22 were set to unknown
Review for gene: MED22 was set to AMBER
Added comment: ESHG talk 2/6/24, unpublished
Elisa Cali, UCL

Recurrent homozygous MED22:c.397_399del (p.Glu133del) inframe variant in 8 individuals from 6 families w progressive NDD, microcepahly, cerebellar atrophy, dystonia, seizures

Rare in gnomad v4.1 (9 het alleles, no homozygotes)

Functional work on patient fibroblasts: quantity of protein comparable to controls, did not mentioned assays of protein function (?mechanism proposed)
Drosophilia heterozygous model with equivalent of p.Glu133del variant: structural anomalies, less movements, all died prior to pupae stage
Zebrafish: MED22 mutants less mobile, died prior to adulthood, reduced brain size
Sources: Other
Mendeliome v1.1976 SF3B1 Mark Cleghorn gene: SF3B1 was added
gene: SF3B1 was added to Mendeliome. Sources: Other
Mode of inheritance for gene: SF3B1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Phenotypes for gene: SF3B1 were set to complex neurodevelopmental disorder MONDO:0100038
Penetrance for gene: SF3B1 were set to unknown
Review for gene: SF3B1 was set to AMBER
Added comment: SF3B1
Delphine Bernard, University of Brest
ESHG talk 2/6/24, unpublished

De novo germline SF3B1 variants, proposed spliceosomopathy/NDD gene

SF3B1 is an RNA binding protein that stabilizes the U2 snRNP complex at branchpoint sequences
Somatic SF3B1 missense commonly occur in haematological malignancy (K700E recurrent)

25 patients with syndromic NDD + de novo heterozygous rare SF3B1 variants identified on WES, genematcher
13 missense (incl recurrent xxx and xxx) within HEAT domain
5 nonsense
4 splicing
1 frameshift

Patients w missense variants may have more severe phenotype incl mircocepahly, palate anomalies, cerebral anomalies, GI/cardiac anomalies

Cellular models of missense variants: erythroleukaemia K562, HEK293T
Suggest missense variants do not cause loss of function, but increase exon skipping and alternative 3’ splice site use
Sources: Other
Mendeliome v1.1976 C12orf66 Mark Cleghorn gene: C12orf66 was added
gene: C12orf66 was added to Mendeliome. Sources: Other
Mode of inheritance for gene: C12orf66 was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: C12orf66 were set to complex neurodevelopmental disorder MONDO:0100038
Penetrance for gene: C12orf66 were set to unknown
Review for gene: C12orf66 was set to AMBER
Added comment: KICS2 (previously known as C12ORF66)
Rebecca Buchert, Universitatklinikum Tubingen
ESHG talk 2/6/24, unpublished

Proposed ID + epilepsy gene

8 families w 11 affected individuals
Phenotypes: 11/11 ID, 9/11 epilepsy, 3/11 hearing impairment
3/8 homozygous missense variants (p.Asp296Glu, p.Tyr393Cys, p.Tyr393Cys), all highly conserved
1/8 compound het PTC (p.Lys262*) with 1.1Mb deletion
4/8 homozygous PTC (p.Glu3*, p.Gly79Valfs*18, p.Gly79Valfs*18, p.Lys260Asnfs*18)

Gene appears to be involved in mTOR pathway, and cilia function
mTORC1 activity in CRISPR-HEK293T cells – reduced activity in cells w variants above

Zebrafish model: otolith defects, ciliary dysfunction
?not clear that this truly mimics phenotype observed in patient cohort described
Sources: Other
Mendeliome v1.1973 REPS2 Mark Cleghorn gene: REPS2 was added
gene: REPS2 was added to Mendeliome. Sources: Other
Mode of inheritance for gene: REPS2 was set to X-LINKED: hemizygous mutation in males, biallelic mutations in females
Phenotypes for gene: REPS2 were set to complex neurodevelopmental disorder MONDO:0100038; Cerebral palsy HP:0100021
Penetrance for gene: REPS2 were set to unknown
Review for gene: REPS2 was set to AMBER
Added comment: REPS2
Hao Hu, Guangzhou Women and Children’s MC
ESHG talk 1/6/24, unpublished

Proposed X-linked cerebral palsy + NDD gene

4 unrelated males with predicted deleterious hemizygous REPS2 variants, 2 PTC, 2 missense. 2 de novo, 2 maternally inherited
Phenotypes: 2 w CP + moderate ID/ASD, 2 w NDD NOS
Variants described:
c.1050_1052delGAA;p.K351del
c.1040T>C; p.I347T
c.962C>G; p.S321C
c.1736delA; p.N579Tfs*17

In vitro assay of above 4 variants suggest reduced REPS2 protein stability
Zebrafish model: REPS2 expressed in neuronal cells, REPS2 knock down have reduced motor activity and abN neuronal morphology
Mouse model hemizygous w one of above variants (not specified): reduced performance in cognitive tasks, abnormal neuronal migration pattern on post mortem examination
Mechanism may relate to dopamine signalling?
Sources: Other
Mendeliome v1.1973 TTL Mark Cleghorn gene: TTL was added
gene: TTL was added to Mendeliome. Sources: Other
Mode of inheritance for gene: TTL was set to BIALLELIC, autosomal or pseudoautosomal
Phenotypes for gene: TTL were set to complex neurodevelopmental disorderMONDO:0100038
Added comment: TTL
Valentina Serpieri, University of Pavia
ESHG talk 1/6/24

FAM1 (Italy)
2 affected sisters born to consanguineous Pakistani parents
GDD, spastic tetraparesis, optic atrophy, brain anomalies resembling tubulinopathies (dysplasia of corpus callosum, basal ganglia, brainstem)
WES: homozygous TTL:c.1013G>A; p.Cys338Tyr in both affected sisters

Via genematcher
5 more families (9 individuals) w similar phenotypes and biallelic variants in TTL

FAM2 (Egypt): homozygous p.Arg46Pro
FAM3 (Egypt): homozygous p.Arg46Pro
FAM4 (Australia): homozygous p.Gln183Arg
FAM5 (France): homozygous p.Trp147*
FAM6 (Saudi Arabia): homozygous p.His243Tyr

TTL KO mice: death soon after birth, no overt malformations, but defects in organisation of cerebral layers

Functional work on patient fibroblasts
FAM1 – reduced quantity of TTL protein compared to control on Western blot, decreased function of TTL protein (increase in detyrosinated tubulin) compared to controls – infer LoF as mechanism
FAM3 – mentioned but no details
FAM4– mentioned but no details
Sources: Other
Mendeliome v1.554 SETD2 Zornitza Stark edited their review of gene: SETD2: Added comment: PMID 32710489: 12 unrelated patients, ranging from 1 month to 12 years of age, with a multisystemic neurodevelopmental disorder associated with a specific de novo heterozygous mutation in the SETD2 gene (R1740W).

Key clinical features: severely impaired global development apparent from infancy, feeding difficulties with failure to thrive, small head circumference, and dysmorphic facial features. Affected individuals have impaired intellectual development and hypotonia; they do not achieve walking or meaningful speech. Other neurologic findings may include seizures, hearing loss, ophthalmologic defects, and brain imaging abnormalities. There is variable involvement of other organ systems, including skeletal, genitourinary, cardiac, and possibly endocrine.

Further 3 unrelated patients identified with mild to moderately impaired intellectual development associated with a specific de novo heterozygous mutation in the SETD2 gene (R1740Q).

These are distinct clinically from Luscan-Lumish syndrome, which is characterised by overgrowth.; Changed publications: 29681085, 32710489; Changed phenotypes: Luscan-Lumish syndrome, MIM#616831, Rabin-Pappas syndrome,MIM# 620155, Intellectual developmental disorder, autosomal dominant 70, MIM# 620157
Mendeliome v1.343 GALK1 Zornitza Stark Tag treatable tag was added to gene: GALK1.
Mendeliome v0.13637 HK1 Zornitza Stark changed review comment from: HMSNR is an autosomal recessive progressive complex peripheral neuropathy characterized by onset in the first decade of distal lower limb weakness and muscle atrophy resulting in walking difficulties. Distal impairment of the upper limbs usually occurs later, as does proximal lower limb weakness. There is distal sensory impairment, with pes cavus and areflexia. Laboratory studies suggest that it is a myelinopathy resulting in reduced nerve conduction velocities in the demyelinating range as well as a length-dependent axonopathy.

Founder variant in the Roma, -3818-195G-C, AltT2 EXON in 5'UTR identified in multiple families.

Note gene is associated with other phenotypes.; to: Bi-allelic variants and neuropathy: HMSNR is an autosomal recessive progressive complex peripheral neuropathy characterized by onset in the first decade of distal lower limb weakness and muscle atrophy resulting in walking difficulties. Distal impairment of the upper limbs usually occurs later, as does proximal lower limb weakness. There is distal sensory impairment, with pes cavus and areflexia. Laboratory studies suggest that it is a myelinopathy resulting in reduced nerve conduction velocities in the demyelinating range as well as a length-dependent axonopathy.

Founder variant in the Roma, -3818-195G-C, AltT2 EXON in 5'UTR identified in multiple families.

Note gene is associated with other phenotypes.
Mendeliome v0.13607 HGD Zornitza Stark Phenotypes for gene: HGD were changed from to Alkaptonuria MIM#203500; Disorders of phenylalanine or tyrosine metabolism
Mendeliome v0.13390 PIEZO2 Zornitza Stark Phenotypes for gene: PIEZO2 were changed from to Marden-Walker syndrome (MIM#248700); Arthrogryposis, distal, type 3 (MIM#114300); Arthrogryposis, distal, type 5 (MIM#108145); Arthrogryposis, distal, with impaired proprioception and touch, MIM# 617146
Mendeliome v0.13387 PIEZO2 Zornitza Stark changed review comment from: Bi-allelic variants: more than 5 unrelated families reported.

Mono-allelic variants:
DA5, more than 20 families reported.
DA3, more than 10 families reported, R2686H is recurrent.; to: Bi-allelic variants: more than 5 unrelated families reported.

Mono-allelic variants:
DA5, more than 20 families reported.
DA3, more than 10 families reported, R2686H is recurrent.
Marden-Walker: 2 families reported.
Mendeliome v0.13387 PIEZO2 Zornitza Stark edited their review of gene: PIEZO2: Changed phenotypes: Marden-Walker syndrome (MIM#248700), Arthrogryposis, distal, type 3 (MIM#114300), Arthrogryposis, distal, type 5 (MIM#108145), Arthrogryposis, distal, with impaired proprioception and touch, MIM# 617146
Mendeliome v0.13387 PIEZO2 Zornitza Stark reviewed gene: PIEZO2: Rating: GREEN; Mode of pathogenicity: None; Publications: 27653382, 27607563, 27843126, 27974811; Phenotypes: Marden-Walker syndrome (MIM#248700), Arthrogryposis, distal, type 3 (MIM#114300), Arthrogryposis, distal, type 5 (MIM#108145); Mode of inheritance: BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Mendeliome v0.13263 RSPH4A Belinda Chong changed review comment from: Radial spokes are regularly spaced along cilia, sperm, and flagella axonemes and have a multisubunit 'stalk' and 'head' that form a signal transduction scaffold between the central microtubule pair and dynein arms. RSPH4A is predicted to be a component of the radial spoke head based on homology with proteins in the biflagellate alga Chlamydomonas reinhardtii and other ciliates (Castleman et al., 2009; PMID19200523)

9 families with primary ciliary dyskinesia without situs inversus (Kott et al. 2013 (PMID:23993197), Castleman et al., 2009 (PMID19200523) and Daniels et al. 2013; (PMID:23798057)):
- In affected members of 4 Pakistani families with CILD11, Castleman et al. (2009) identified a homozygous mutation in the RSPH4A gene.
- In affected members of a family of northern European descent with CILD11, Castleman et al. (2009) identified compound heterozygosity for 2 mutations in the RSPH4A gene
- Kott et al. (2013) identified pathogenic mutations in the RSPH4A gene in 7 (14%) of 48 families with a specific CILD.

Common founder mutation:
- Daniels et al. (2013) identified a common founder mutation in the RSPH4A gene in 9 patients with CILD11, all of whom had Puerto Rican ancestry.

Multiple individuals in ClinVar with primary ciliary dyskinesia; to: Radial spokes are regularly spaced along cilia, sperm, and flagella axonemes and have a multisubunit 'stalk' and 'head' that form a signal transduction scaffold between the central microtubule pair and dynein arms. RSPH4A is predicted to be a component of the radial spoke head based on homology with proteins in the biflagellate alga Chlamydomonas reinhardtii and other ciliates (Castleman et al., 2009; PMID19200523)

9 families with primary ciliary dyskinesia without situs inversus (Kott et al. 2013 (PMID:23993197), Castleman et al., 2009 (PMID19200523) and Daniels et al. 2013; (PMID:23798057)):
- In affected members of 4 Pakistani families with CILD11, Castleman et al. (2009) identified a homozygous mutation in the RSPH4A gene.
- In affected members of a family of northern European descent with CILD11, Castleman et al. (2009) identified compound heterozygosity for 2 mutations in the RSPH4A gene
- Kott et al. (2013) identified pathogenic mutations in the RSPH4A gene in 7 (14%) of 48 families with a specific CILD.

Common founder mutation:
- Daniels et al. (2013) identified a common founder mutation in the RSPH4A gene in 9 patients with CILD11, all of whom had Puerto Rican ancestry.

Multiple individuals in ClinVar with primary ciliary dyskinesia

PMID: 25789548; Frommer 2015: 8 PCD families reported, only 4 different variants identified. Functional studies performed.

PMID: 22448264; Ziętkiewicz 2012: 4 additional families/variants reported.
Mendeliome v0.12790 EXOC3L2 Bryony Thompson Phenotypes for gene: EXOC3L2 were changed from Dandy-Walker malformation; renal dysplasia; bone marrow failure to Dandy-Walker malformation, MONDO:0009072; renal dysplasia; bone marrow failure
Mendeliome v0.11753 SARS2 Zornitza Stark Phenotypes for gene: SARS2 were changed from to Hyperuricemia, pulmonary hypertension, renal failure, and alkalosis, MIM#613845
Mendeliome v0.11750 SARS2 Zornitza Stark reviewed gene: SARS2: Rating: GREEN; Mode of pathogenicity: None; Publications: 33751860; Phenotypes: Hyperuricemia, pulmonary hypertension, renal failure, and alkalosis, MIM#613845; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Mendeliome v0.11719 SARS2 Samantha Ayres reviewed gene: SARS2: Rating: GREEN; Mode of pathogenicity: None; Publications: 24034276, 21255763; Phenotypes: Hyperuricemia, pulmonary hypertension, renal failure, and alkalosis, MIM#613845; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Mendeliome v0.11295 KIAA1109 Zornitza Stark changed review comment from: ALKKUCS is an autosomal recessive severe neurodevelopmental disorder characterized by arthrogryposis, brain abnormalities associated with cerebral parenchymal underdevelopment, and global developmental delay. Most affected individuals die in utero or soon after birth. Additional abnormalities may include hypotonia, dysmorphic facial features, and involvement of other organ systems, such as cardiac or renal. The few patients who survive have variable intellectual disability and may have seizures.; to: ALKKUCS is an autosomal recessive severe neurodevelopmental disorder characterized by arthrogryposis, brain abnormalities associated with cerebral parenchymal underdevelopment, and global developmental delay. Most affected individuals die in utero or soon after birth. Additional abnormalities may include hypotonia, dysmorphic facial features, and involvement of other organ systems, such as cardiac or renal. The few patients who survive have variable intellectual disability and may have seizures.

More than 10 families reported.
Mendeliome v0.11295 KIAA1109 Zornitza Stark Phenotypes for gene: KIAA1109 were changed from to Alkuraya-Kucinskas syndrome, MIM# 617822
Mendeliome v0.11292 KIAA1109 Zornitza Stark reviewed gene: KIAA1109: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: Alkuraya-Kucinskas syndrome, MIM# 617822; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Mendeliome v0.10728 ZIC4 Zornitza Stark Added comment: Comment when marking as ready: Two individuals reported with a deletion of ZIC1 and ZIC4 and Dandy-Walker malformation.
Mendeliome v0.10552 SLC35F1 Ain Roesley gene: SLC35F1 was added
gene: SLC35F1 was added to Mendeliome. Sources: Literature
Mode of inheritance for gene: SLC35F1 was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown
Publications for gene: SLC35F1 were set to 33821533
Phenotypes for gene: SLC35F1 were set to Rett-like syndrome
Penetrance for gene: SLC35F1 were set to unknown
Review for gene: SLC35F1 was set to RED
gene: SLC35F1 was marked as current diagnostic
Added comment: WES found a de novo heterozygous c.1037T>C; p.(I346T) (absent in gnomad v2 and v3) in a female described to have Rett-like syndrome.

Global developmental delay, generalized tonic andtonic–clonic seizure, never acquired independent walking and developed spastictetraplegia in adulthood and limited speech

no protein functional work was performed
Sources: Literature
Mendeliome v0.10224 GALK1 Zornitza Stark Marked gene: GALK1 as ready
Mendeliome v0.10224 GALK1 Zornitza Stark Gene: galk1 has been classified as Green List (High Evidence).
Mendeliome v0.10215 GALK1 Zornitza Stark Phenotypes for gene: GALK1 were changed from to Galactokinase deficiency with cataracts MIM#230200; Disorders of galactose metabolism
Mendeliome v0.10214 GALK1 Zornitza Stark Publications for gene: GALK1 were set to
Mendeliome v0.10213 GALK1 Zornitza Stark Mode of inheritance for gene: GALK1 was changed from Unknown to BIALLELIC, autosomal or pseudoautosomal
Mendeliome v0.10181 ADCY5 Zornitza Stark edited their review of gene: ADCY5: Added comment: Neurodevelopmental disorder with hyperkinetic movements and dyskinesia (NEDHYD) is an autosomal recessive complex neurologic disorder characterized by severe global developmental delay with axial hypotonia, impaired intellectual development, poor overall growth, and abnormal involuntary hyperkinetic movements, including dystonia, myoclonus, spasticity, and orofacial dyskinesia. It is the most severe manifestation of ADCY5-related dyskinetic disorders. Five individuals from 2 families reported.

Autosomal recessive hyperkinetic movement disorder with dyskinesia, myoclonus, chorea, and dystonia-2 (HYDMCD2) is characterized by the onset of abnormal involuntary movements, mainly affecting the limbs and causing walking difficulties, in the first decade. The severity is variable; some patients have orofacial dyskinesia, resulting in speech difficulties, or develop neuropsychiatric features, including anxiety and social withdrawal. Cardiomyopathy has rarely been described and may be a manifestation of the disorder. Eight individuals from 2 families reported.; Changed publications: 22782511, 24700542, 33051786, 32647899, 33704598, 34631954, 28971144, 30975617; Changed phenotypes: Dyskinesia, familial, with facial myokymia, MIM# 606703, MONDO:0011707, Hyperkinetic movement disorder with dyskinesia, myoclonus, chorea, and dystonia-2 (HYDMCD2), MIM#619647, Neurodevelopmental disorder with hyperkinetic movements and dyskinesia (NEDHYD), MIM#619651; Changed mode of inheritance: BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Mendeliome v0.10041 SMPX Zornitza Stark edited their review of gene: SMPX: Added comment: PMID 33974137: Four different missense variants were identified in ten patients from nine families in five different countries. Haplotype analysis of patients with similar ancestry revealed two different founder mutations in Southern Europe and France, indicating that the prevalence in these populations may be higher. Clinical features: adult-onset, usually distal more than proximal limb muscle weakness, slowly progressing over decades with preserved walking. Lower limb muscle imaging showed a characteristic pattern of muscle involvement and fatty degeneration. Histopathological and electron microscopic analysis of patient muscle biopsies revealed myopathic findings with rimmed vacuoles and the presence of sarcoplasmic inclusions, some with amyloid-like characteristics. In silico predictions and subsequent cell culture studies showed that the missense mutations increase aggregation propensity of the SMPX protein. In cell culture studies, overexpressed SMPX localized to stress granules and slowed down their clearance.; Changed publications: 21549342, 21549336, 21893181, 22911656, 28542515, 33974137; Changed phenotypes: Deafness, X-linked 4, MIM# 300066, Distal myopathy, adult-onset
Mendeliome v0.9915 DAG1 Zornitza Stark reviewed gene: DAG1: Rating: GREEN; Mode of pathogenicity: None; Publications: 21388311, 25934851, 24052401, 25503980; Phenotypes: Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 9, Muscular dystrophy-dystroglycanopathy (limb-girdle), type C, 9, 613818, Walker-Warburg syndrome and tectocerebellar dysgraphia; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Mendeliome v0.9779 KIAA1109 Ain Roesley reviewed gene: KIAA1109: Rating: GREEN; Mode of pathogenicity: None; Publications: 29290337, 30906834; Phenotypes: Alkuraya-Kucinskas syndrome MIM#617822; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal; Current diagnostic: yes
Mendeliome v0.9355 SLC4A3 Daniel Flanagan gene: SLC4A3 was added
gene: SLC4A3 was added to Mendeliome. Sources: Expert Review
Mode of inheritance for gene: SLC4A3 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Publications for gene: SLC4A3 were set to PMID: 29167417; 34557911
Phenotypes for gene: SLC4A3 were set to Short QT syndrome
Review for gene: SLC4A3 was set to AMBER
Added comment: Moderate evidence for autosomal dominant short QT syndrome 1 by ClinGen /gene curation expert panel (PMID: 34557911). A single missense variant (absent gnomAD) identified in two SQTS families. In family 1, it segregated with SQTS (QTc<370ms) in 23 carriers, and 19 non-carriers had a QTc>370ms. In family 2, it segregated in 4 individuals. Experimental evidence from in vitro and zebrafish models suggests reduced membrane localization of the mutated protein leads to intracellular alkalinization and shortening of the cardiomyocyte action potential duration.
ClinGen expert panel was divided between strong (4 votes) and moderate (5 votes).
Sources: Expert Review
Mendeliome v0.8823 SLC51A Zornitza Stark gene: SLC51A was added
gene: SLC51A was added to Mendeliome. Sources: Literature
Mode of inheritance for gene: SLC51A was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: SLC51A were set to 31863603
Phenotypes for gene: SLC51A were set to Cholestasis, progressive familial intrahepatic, 6, MIM# 619484
Review for gene: SLC51A was set to RED
Added comment: Single individual reported with homozygous LoF variant, who presented with chronic malabsorptive diarrhoea, easy bruising, episodes of prolonged bleeding that required blood transfusions, and failure to thrive. Laboratory testing at age 2.5 years showed elevated liver transaminases and alkaline phosphatase. Liver biopsy demonstrated portal and periportal fibrosis and hepatocytes with foci of hepatocytic cholestasis. Analysis of bile acids in a blood spot were normal. Treatment with ursodiol and cholestyramine was started at 5 years of age. The coagulopathy resolved and his growth was adequate, but his liver transaminases, direct bilirubin, and GGT levels remained elevated.
Sources: Literature
Mendeliome v0.8428 SCNN1G Zornitza Stark edited their review of gene: SCNN1G: Added comment: Variants resulting in constitutive activation of epithelial sodium channel activity have been demonstrated in the beta and gamma subunits as the cause of the autosomal dominant form of hypertension, Liddle syndrome, which is characterized by volume expansion, hypokalemia, and alkalosis.

Variants causing loss of epithelial sodium channel activity cause the converse phenotype of volume depletion, hyperkalaemia and acidosis characteristic of patients with pseudohypoaldosteronism type I.

Well established gene-disease associations.; Changed rating: GREEN; Changed phenotypes: Liddle syndrome 2, MIM# 618114, Pseudohypoaldosteronism, type I, MIM# 264350; Changed mode of inheritance: BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Mendeliome v0.8318 ATG7 Zornitza Stark changed review comment from: 12 individuals from 5 unrelated families reported with a complex neurodevelopmental disorder and bi-allelic variants in this gene. Age range from 21 months to 71 years of age. Main clinical features included axial hypotonia, variably impaired intellectual development with poor or absent speech, and delayed walking (up to 7 years of age) or inability to walk. All had ataxia, often with tremor or dyskinesia, as well as dysarthria associated with cerebellar hypoplasia on brain imaging. Most had optic atrophy, and some had ptosis, chronic progressive external ophthalmoplegia, retinopathy, and strabismus; 1 had early-onset cataracts. The ore severely affected individuals had spastic paraplegia and inability to walk.

Functional data including mouse model.
Sources: Literature; to: 12 individuals from 5 unrelated families reported with a complex neurodevelopmental disorder and bi-allelic variants in this gene. Age range from 21 months to 71 years of age. Main clinical features included axial hypotonia, variably impaired intellectual development with poor or absent speech, and delayed walking (up to 7 years of age) or inability to walk. All had ataxia, often with tremor or dyskinesia, as well as dysarthria associated with cerebellar hypoplasia on brain imaging. Most had optic atrophy, and some had ptosis, chronic progressive external ophthalmoplegia, retinopathy, and strabismus; 1 had early-onset cataracts. The more severely affected individuals had spastic paraplegia and inability to walk.

Functional data including mouse model.
Sources: Literature
Mendeliome v0.8318 ATG7 Zornitza Stark changed review comment from: 12 individuals from 5 unrelated families reported with a complex neurodevelopmental disorder and bi-allelic variants in this gene. Age range from 21 months to 71 years of age. Main clinical features included axial hypotonia, variably impaired intellectual development with poor or absent speech, and delayed walking (up to 7 years of age) or inability to walk. All had ataxia, often with tremor or dyskinesia, as well as dysarthria associated with cerebellar hypoplasia on brain imaging. Most had optic atrophy, and some had ptosis, chronic progressive external ophthalmoplegia, retinopathy, and strabismus; 1 had early-onset cataracts. The ore severely affected individuals had spastic paraplegia and inability to walk.
Sources: Literature; to: 12 individuals from 5 unrelated families reported with a complex neurodevelopmental disorder and bi-allelic variants in this gene. Age range from 21 months to 71 years of age. Main clinical features included axial hypotonia, variably impaired intellectual development with poor or absent speech, and delayed walking (up to 7 years of age) or inability to walk. All had ataxia, often with tremor or dyskinesia, as well as dysarthria associated with cerebellar hypoplasia on brain imaging. Most had optic atrophy, and some had ptosis, chronic progressive external ophthalmoplegia, retinopathy, and strabismus; 1 had early-onset cataracts. The ore severely affected individuals had spastic paraplegia and inability to walk.

Functional data including mouse model.
Sources: Literature
Mendeliome v0.8317 ATG7 Zornitza Stark gene: ATG7 was added
gene: ATG7 was added to Mendeliome. Sources: Literature
Mode of inheritance for gene: ATG7 was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: ATG7 were set to 34161705
Phenotypes for gene: ATG7 were set to Spinocerebellar ataxia, SCAR31, MIM#619422
Review for gene: ATG7 was set to GREEN
Added comment: 12 individuals from 5 unrelated families reported with a complex neurodevelopmental disorder and bi-allelic variants in this gene. Age range from 21 months to 71 years of age. Main clinical features included axial hypotonia, variably impaired intellectual development with poor or absent speech, and delayed walking (up to 7 years of age) or inability to walk. All had ataxia, often with tremor or dyskinesia, as well as dysarthria associated with cerebellar hypoplasia on brain imaging. Most had optic atrophy, and some had ptosis, chronic progressive external ophthalmoplegia, retinopathy, and strabismus; 1 had early-onset cataracts. The ore severely affected individuals had spastic paraplegia and inability to walk.
Sources: Literature
Mendeliome v0.7706 RAB11B Zornitza Stark commented on gene: RAB11B: NDAGSCW is a neurodevelopmental disorder characterized by severely delayed psychomotor development apparent from infancy. Affected individuals have delayed and difficulty walking, intellectual disability, absent speech, and variable additional features, including hip dysplasia, tapering fingers, and seizures. Brain imaging shows decreased cortical white matter, often with decreased cerebellar white matter, thin corpus callosum, and thin brainstem.
Mendeliome v0.6808 SATB1 Zornitza Stark edited their review of gene: SATB1: Added comment: Kohlschutter-Tonz syndrome-like (KTZSL) is characterized by global developmental delay with moderately to severely impaired intellectual development, poor or absent speech, and delayed motor skills. Although the severity of the disorder varies, many patients are nonverbal and have hypotonia with inability to sit or walk. Early-onset epilepsy is common and may be refractory to treatment, leading to epileptic encephalopathy and further interruption of developmental progress. Most patients have feeding difficulties with poor overall growth and dysmorphic facial features, as well as significant dental anomalies resembling amelogenesis imperfecta. This phenotype was reported in 28 patients (patients 13 to 40, PMID 33513338), including 9 patients from 3 families. Most variants were de novo, though some were inherited, suggestive of incomplete penetrance and variable expressivity.; Changed phenotypes: Developmental delay with dysmorphic facies and dental anomalies, MIM# 619228, Kohlschutter-Tonz syndrome-like, MIM# 619229
Mendeliome v0.6808 SATB1 Zornitza Stark commented on gene: SATB1: Developmental delay with dysmorphic facies and dental anomalies (DEFDA) is characterized by generally mild global developmental delay with variably impaired intellectual development, walking by 2 to 3 years, and slow language acquisition. The severity of the disorder ranges from moderate cognitive deficits to mild learning difficulties or behavioral abnormalities. Most patients have dysmorphic facial features, often with abnormal dentition and nonspecific visual defects, such as myopia, astigmatism, and strabismus. Although rare, involvement of other systems, such as skeletal, cardiac, and gastrointestinal, may be present. 12 individuals from 11 families reported (one inherited variant, affected parent).
Mendeliome v0.6684 CYP2U1 Zornitza Stark edited their review of gene: CYP2U1: Added comment: SPG56 is an autosomal recessive neurodegenerative disorder characterized by early-onset progressive lower-limb spasticity resulting in walking difficulties. Upper limbs are often also affected, and some patients may have a subclinical axonal neuropathy. Onset is typically in the first decade. More than 5 unrelated families reported.; Changed rating: GREEN; Changed publications: 23176821, 32006740, 29034544
Mendeliome v0.6187 PIGF Paul De Fazio changed review comment from: The same homozygous missense variant identified in 2 individuals from different families from the same region of India. Individuals had a phenotype similar to DOORS syndrome without deafness. Impaired glycosylphosphatidylinositol (GPI) biosynthesis was demonstrated.

Rated Red as the two families are likely to be related (founder mutation?).
Sources: Literature; to: The same homozygous missense variant identified in 2 individuals from different families from the same region of India. Individuals had a phenotype similar to DOORS syndrome without deafness - only one of the two had seizures (GTCS), the other was 14mo and noted to have tonic posturing.

Impaired glycosylphosphatidylinositol (GPI) biosynthesis was demonstrated by flow cytometry and a rescue assay. Alkaline phosphatase in both individuals was normal.

Rated Red as the two families are likely to be related (founder mutation?).
Sources: Literature
Mendeliome v0.6035 SCAMP5 Zornitza Stark edited their review of gene: SCAMP5: Added comment: PMID 33390987: Four unrelated individuals reported with same de novo missense variant, p. Gly180Trp. The onset age of seizures was ranged from 6 to 15 months. Patients had different types of seizures, including focal seizures, generalized tonic-clonic seizures and tonic seizure. One patient showed typical autism spectrum disorder (ASD) symptoms. Electroencephalogram (EEG) findings presented as focal or multifocal discharges, sometimes spreading to generalization. Brain magnetic resonance imaging (MRI) abnormalities were present in each patient. Severe intellectual disability and language and motor developmental disorders were found in our patients, with all patients having poor language development and were nonverbal at last follow-up. All but one of the patients could walk independently in childhood, but the ability to walk independently in one patient had deteriorated with age. All patients had abnormal neurological exam findings, mostly signs of extrapyramidal system involvement. Dysmorphic features were found in 2/4 patients, mainly in the face and trunk.; Changed publications: 31439720, 33390987
Mendeliome v0.5914 DPH2 Paul De Fazio changed review comment from: One family reported (PMID:32576952) with biallelic (one missense, one nonsense) variants in DPH2, with phenotype similar to DPH1 deficiency.

Another family was previously reported with biallelic nonsense variants (PMID:27421267) with a comparable phenotype, this family also has biallelic variants in KALRN and the authors thought those variants more likely causative.

In vitro functional assays support reduced diphthamide synthesis activity for the variants identified in PMID:32576952.
Sources: Literature; to: One 19 month old reported (PMID:32576952) with biallelic (one missense, one nonsense) variants in DPH2, with phenotype similar to DPH1 deficiency (gross motor delay, not walking, fine motor and expressive language delays, macrocephaly)

Another family (sibs) was previously reported with biallelic nonsense variants (PMID:27421267) with a comparable phenotype, this family also has biallelic variants in KALRN and the authors thought those variants more likely causative. Patients had ID and microcephaly (in contrast to the 19 month old above).

In vitro functional assays support reduced diphthamide synthesis activity for the variants identified in PMID:32576952.
Sources: Literature
Mendeliome v0.5567 VPS4A Kristin Rigbye changed review comment from: PMID: 33186543 - 2x de novo hetorozygous missense variants in the AAA (large ATPase) domain.
1x homozygous missense in the MIT domain (milder phenotype and unaffected parents).
Demonstrated defective CD71 trafficking in all 3 patients.

PMID: 33186545 - 6x probands with de novo missense variants in the AAA domain. 5 of the variants were at amino acid position 284 (changes to Trp and Gly).
Demonstrated that the variants had a dominant-negative effect on VPS4A function.
"The six probands with de novo substitutions affecting Glu206 or Arg284 had a consistent phenotype characterized by severe DD, profound ID, and dystonia. Children were very delayed in establishing head control and none achieved independent walking. Other common findings were cerebellar hypoplasia (five individuals out of six, the other showing uncharacterized severe cerebral atrophy) with a variable degree of corpus callosum hypoplasia. One individual also had bilateral polymicrogyria. Epilepsy was present in three and dystonia in five subjects. Eye involvement was also a common finding, including congenital cataract, retinal dystrophy, and in one case congenital Leber amaurosis. Four individuals were diagnosed with hepatosplenomegaly and/or steatosis. Three subjects had anemia, which was characterized as dyserythropoietic in two. Severe feeding difficulties were present in four individuals, requiring assisted feeding in three. Two had sensorineural deafness. Severe growth retardation, generally for all parameters, was present in most cases. Notably, severe microcephaly (typically with Z scores < −5) was universal. Overall, the disorder seems to have a poor prognosis as two affected individuals died in childhood or early adult life."
Sources: Literature; to: PMID: 33186543 - 2x de novo hetorozygous missense variants in the AAA (large ATPase) domain.
1x homozygous missense in the MIT domain (milder phenotype and unaffected parents - possibly just a simple LoF mechanism for AR inheritance).
Demonstrated defective CD71 trafficking in all 3 patients.

PMID: 33186545 - 6x probands with de novo missense variants in the AAA domain. 5 of the variants were at amino acid position 284 (changes to Trp and Gly).
Demonstrated that the variants had a dominant-negative effect on VPS4A function.

"The six probands with de novo substitutions affecting Glu206 or Arg284 had a consistent phenotype characterized by severe DD, profound ID, and dystonia. Children were very delayed in establishing head control and none achieved independent walking. Other common findings were cerebellar hypoplasia (five individuals out of six, the other showing uncharacterized severe cerebral atrophy) with a variable degree of corpus callosum hypoplasia. One individual also had bilateral polymicrogyria. Epilepsy was present in three and dystonia in five subjects. Eye involvement was also a common finding, including congenital cataract, retinal dystrophy, and in one case congenital Leber amaurosis. Four individuals were diagnosed with hepatosplenomegaly and/or steatosis. Three subjects had anemia, which was characterized as dyserythropoietic in two. Severe feeding difficulties were present in four individuals, requiring assisted feeding in three. Two had sensorineural deafness. Severe growth retardation, generally for all parameters, was present in most cases. Notably, severe microcephaly (typically with Z scores < −5) was universal. Overall, the disorder seems to have a poor prognosis as two affected individuals died in childhood or early adult life."
Mendeliome v0.5567 VPS4A Elena Savva changed review comment from: Comment when marking as ready: PMID: 33186543 - 2x de novo hetorozygous missense variants in the AAA (large ATPase) domain. 1x homozygous missense in the MIT domain (milder phenotype and unaffected parents). Demonstrated defective CD71 trafficking in all 3 patients. PMID: 33186545 - 6x probands with de novo missense variants in the AAA domain. 5 of the variants were at amino acid position 284 (changes to Trp and Gly). Demonstrated that the variants had a dominant-negative effect on VPS4A function. "The six probands with de novo substitutions affecting Glu206 or Arg284 had a consistent phenotype characterized by severe DD, profound ID, and dystonia. Children were very delayed in establishing head control and none achieved independent walking. Other common findings were cerebellar hypoplasia (five individuals out of six, the other showing uncharacterized severe cerebral atrophy) with a variable degree of corpus callosum hypoplasia. One individual also had bilateral polymicrogyria. Epilepsy was present in three and dystonia in five subjects. Eye involvement was also a common finding, including congenital cataract, retinal dystrophy, and in one case congenital Leber amaurosis. Four individuals were diagnosed with hepatosplenomegaly and/or steatosis. Three subjects had anemia, which was characterized as dyserythropoietic in two. Severe feeding difficulties were present in four individuals, requiring assisted feeding in three. Two had sensorineural deafness. Severe growth retardation, generally for all parameters, was present in most cases. Notably, severe microcephaly (typically with Z scores < −5) was universal. Overall, the disorder seems to have a poor prognosis as two affected individuals died in childhood or early adult life."; to: PMID: 33186543 - 2x de novo hetorozygous missense variants in the AAA (large ATPase) domain.
1x homozygous missense in the MIT domain (milder phenotype and unaffected parents).
Demonstrated defective CD71 trafficking in all 3 patients.

Comment when marking as ready: PMID: 33186543 - 2x de novo hetorozygous missense variants in the AAA (large ATPase) domain. 1x homozygous missense in the MIT domain (milder phenotype and unaffected parents). Demonstrated defective CD71 trafficking in all 3 patients. PMID: 33186545 - 6x probands with de novo missense variants in the AAA domain. 5 of the variants were at amino acid position 284 (changes to Trp and Gly). Demonstrated that the variants had a dominant-negative effect on VPS4A function. "The six probands with de novo substitutions affecting Glu206 or Arg284 had a consistent phenotype characterized by severe DD, profound ID, and dystonia. Children were very delayed in establishing head control and none achieved independent walking. Other common findings were cerebellar hypoplasia (five individuals out of six, the other showing uncharacterized severe cerebral atrophy) with a variable degree of corpus callosum hypoplasia. One individual also had bilateral polymicrogyria. Epilepsy was present in three and dystonia in five subjects. Eye involvement was also a common finding, including congenital cataract, retinal dystrophy, and in one case congenital Leber amaurosis. Four individuals were diagnosed with hepatosplenomegaly and/or steatosis. Three subjects had anemia, which was characterized as dyserythropoietic in two. Severe feeding difficulties were present in four individuals, requiring assisted feeding in three. Two had sensorineural deafness. Severe growth retardation, generally for all parameters, was present in most cases. Notably, severe microcephaly (typically with Z scores < −5) was universal. Overall, the disorder seems to have a poor prognosis as two affected individuals died in childhood or early adult life."
Mendeliome v0.5567 VPS4A Elena Savva Added comment: Comment when marking as ready: PMID: 33186543 - 2x de novo hetorozygous missense variants in the AAA (large ATPase) domain. 1x homozygous missense in the MIT domain (milder phenotype and unaffected parents). Demonstrated defective CD71 trafficking in all 3 patients. PMID: 33186545 - 6x probands with de novo missense variants in the AAA domain. 5 of the variants were at amino acid position 284 (changes to Trp and Gly). Demonstrated that the variants had a dominant-negative effect on VPS4A function. "The six probands with de novo substitutions affecting Glu206 or Arg284 had a consistent phenotype characterized by severe DD, profound ID, and dystonia. Children were very delayed in establishing head control and none achieved independent walking. Other common findings were cerebellar hypoplasia (five individuals out of six, the other showing uncharacterized severe cerebral atrophy) with a variable degree of corpus callosum hypoplasia. One individual also had bilateral polymicrogyria. Epilepsy was present in three and dystonia in five subjects. Eye involvement was also a common finding, including congenital cataract, retinal dystrophy, and in one case congenital Leber amaurosis. Four individuals were diagnosed with hepatosplenomegaly and/or steatosis. Three subjects had anemia, which was characterized as dyserythropoietic in two. Severe feeding difficulties were present in four individuals, requiring assisted feeding in three. Two had sensorineural deafness. Severe growth retardation, generally for all parameters, was present in most cases. Notably, severe microcephaly (typically with Z scores < −5) was universal. Overall, the disorder seems to have a poor prognosis as two affected individuals died in childhood or early adult life."
Mendeliome v0.5558 VPS4A Kristin Rigbye gene: VPS4A was added
gene: VPS4A was added to Mendeliome. Sources: Literature
Mode of inheritance for gene: VPS4A was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Publications for gene: VPS4A were set to PMID: 33186543; 33186545
Phenotypes for gene: VPS4A were set to Neurodevelopmental disorder
Review for gene: VPS4A was set to GREEN
Added comment: PMID: 33186543 - 2x de novo hetorozygous missense variants in the AAA (large ATPase) domain.
1x homozygous missense in the MIT domain (milder phenotype and unaffected parents).
Demonstrated defective CD71 trafficking in all 3 patients.

PMID: 33186545 - 6x probands with de novo missense variants in the AAA domain. 5 of the variants were at amino acid position 284 (changes to Trp and Gly).
Demonstrated that the variants had a dominant-negative effect on VPS4A function.
"The six probands with de novo substitutions affecting Glu206 or Arg284 had a consistent phenotype characterized by severe DD, profound ID, and dystonia. Children were very delayed in establishing head control and none achieved independent walking. Other common findings were cerebellar hypoplasia (five individuals out of six, the other showing uncharacterized severe cerebral atrophy) with a variable degree of corpus callosum hypoplasia. One individual also had bilateral polymicrogyria. Epilepsy was present in three and dystonia in five subjects. Eye involvement was also a common finding, including congenital cataract, retinal dystrophy, and in one case congenital Leber amaurosis. Four individuals were diagnosed with hepatosplenomegaly and/or steatosis. Three subjects had anemia, which was characterized as dyserythropoietic in two. Severe feeding difficulties were present in four individuals, requiring assisted feeding in three. Two had sensorineural deafness. Severe growth retardation, generally for all parameters, was present in most cases. Notably, severe microcephaly (typically with Z scores < −5) was universal. Overall, the disorder seems to have a poor prognosis as two affected individuals died in childhood or early adult life."
Sources: Literature
Mendeliome v0.5507 USP7 Zornitza Stark edited their review of gene: USP7: Added comment: Hao-Fountain syndrome (HAFOUS) is a neurodevelopmental disorder characterized by global developmental delay, variably impaired intellectual development with significant speech delay, behavioral abnormalities, such as autism, and mild dysmorphic facies. Additional features are variable, but may include hypotonia, feeding problems, delayed walking with unsteady gait, hypogonadism in males, and ocular anomalies, such as strabismus. Some patients develop seizures and some have mild white matter abnormalities on brain imaging.; Changed publications: 26365382, 30679821; Changed phenotypes: Hao-Fountain syndrome, MIM# 616863, Intellectual disability, Autism
Mendeliome v0.5264 ALK Zornitza Stark Marked gene: ALK as ready
Mendeliome v0.5264 ALK Zornitza Stark Gene: alk has been classified as Green List (High Evidence).
Mendeliome v0.5264 ALK Zornitza Stark Phenotypes for gene: ALK were changed from to {Neuroblastoma, susceptibility to, 3} 613014; Spastic-dystonic diplegia
Mendeliome v0.5263 ALK Zornitza Stark Publications for gene: ALK were set to
Mendeliome v0.5262 ALK Zornitza Stark Mode of inheritance for gene: ALK was changed from Unknown to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Mendeliome v0.5261 ALK Zornitza Stark reviewed gene: ALK: Rating: GREEN; Mode of pathogenicity: None; Publications: 32989326, 18724359; Phenotypes: {Neuroblastoma, susceptibility to, 3} 613014, Spastic-dystonic diplegia; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Mendeliome v0.4998 CSNK1G1 Zornitza Stark gene: CSNK1G1 was added
gene: CSNK1G1 was added to Mendeliome. Sources: Literature
Mode of inheritance for gene: CSNK1G1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Publications for gene: CSNK1G1 were set to 33009664
Phenotypes for gene: CSNK1G1 were set to Global developmental delay; Intellectual disability; Autism; Seizures
Review for gene: CSNK1G1 was set to GREEN
Added comment: Borderline Green/Amber rating.

Gold et al (2020 - PMID: 33009664) report 5 individuals with CSNK1G1 variants, including updated information on a previously reported subject (Martin et al 2014 - PMID: 24463883).

Features included DD (5/5) with associated expressive language delay, ASD (in at least 3/5), seizures (2/5), dysmorphic facial features (4/5 arched eyebrows, 3/5 prominent central incisors, 2/5 epicanthus) and limb anomalies (2/5 - proximally placed thumb, 5th f. clinodactyly, asymmetric overgrowth - the other individual had tapering fingers). GI problems were observed in 4/5. Two individuals had macrocephaly and one had microcephaly. There was no formal developmental assessment although ID might be implied in at least 3 individuals (p1: 20y - single words/regression in walking following a seizure episode, p2: 8y - first words at 5y, assistance to feed, dress and bathe, ASD, p4: 13y - regression, assistance to feed and dress).

CSNK1G1 encodes the gamma-1 isoform of casein kinase 1, a protein involved in growth and cell morphogenesis. The gene has ubiquitous expression, incl. brain. As commented, in brain it regulates phosphorylation of NMDA receptors, playing a role in synaptic transmission (4 articles cited).

One individual had a 1.2 kb deletion spanning exon 3 of CSNK1G1 [chr15:64550952-64552120 - GRCh37]. Parental samples were unavailable for this individual. Four individuals were found to harbor de novo CSNK1G1 variants [NM_022048.3: c.688C>T - p.(Arg230Trp) dn | c.1255C>T - p.(Gln419*) dn | c.1214+5G>A dn with in silico predictions in favor of splice disruption | c.419C>T - p.(Thr140Met) dn].

Arg230Trp is however present once in gnomAD. The stopgain variant is located in the last exon and predicted to skip NMD.

There were no variant studies performed.

The Drosophila gish gene encodes a CK1γ homolog with preferential expression in the mushroom body. Heterozygous and homozygous mutants exhibit impairment in memory retention, more severe in homozygous flies. gish was also identified as a seizure modifier in a fly epilepsy model (heterozygous para mt flies).
Sources: Literature
Mendeliome v0.4860 VPS16 Zornitza Stark gene: VPS16 was added
gene: VPS16 was added to Mendeliome. Sources: Literature
Mode of inheritance for gene: VPS16 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Publications for gene: VPS16 were set to 32808683
Phenotypes for gene: VPS16 were set to Dystonia
Added comment: 18 individuals reported with high-impact variants in VPS16 and a progressive early onset dystonia (median age 12 years, range 3–50 years), with prominent oromandibular, bulbar, cervical, and upper limb involvement. Progressive generalization ensued, although most remained ambulant, and only a minority (16%) lost the ability to walk in adulthood. Additional clinical features of mild to moderate intellectual disability and neuropsychiatric symptoms were present in approximately one‐third. In 4 individuals, magnetic resonance imaging (MRI) showed bilateral and symmetrical hypointensity of the globi pallidi and sometimes also the midbrain and dentate nuclei, suggestive of iron deposition. Mild generalized cerebral atrophy was also apparent in 4 individuals.
Sources: Literature
Mendeliome v0.4520 SLC12A2 Zornitza Stark edited their review of gene: SLC12A2: Added comment: Monoallelic :
DD/ID was a feature in >= 6 individuals with monoallelic de novo SLC12A2. An individual with an exon 22 truncating variant was reported to have normal milestones and cognitive function. Exon 21 variants have been described in individuals with rather isolated hearing impairment (possibly some associated motor delay, but normal cognition). Hearing impairment was also reported in 2/6 patients with variants in other exons (1 missense / 1 frameshift).

Biallelic :
DD/ID was reported in at least 3 individuals in literature. Hearing impairment has been reported on 2 occasions (although this was not probably evaluated in all subjects).

---

Monoallelic SLC12A2 mutations :

► Individuals with de novo mutations and developmental disorder were first identified by the DDD study (2017 - PMID: 28135719). 5 of them have been reported in detail by McNeill et al (below).

► McNeill et al (2020 - PMID: 32658972) report on 6 individuals with neurodevelopmental disorder due to de novo SLC12A2 mutation. All presented DD or ID ranging from mild to severe. ASD was reported in 3/6. Sensorineural hearing loss was a feature in 2/6 with the remaining having normal formal evaluations. Brain, cardiac and/or additional malformations were reported in a single individual. Following non-diagnostic prior work-up (CMA, FMR1 or other investigations) trio exome sequencing revealed missense (4/6) or truncating variants (2/6).

Three additional individuals (incl. a father and his son) with missense variants in exon 21 (NM_001046.3 / p.Glu979Lys and p.Glu980Lys) presented with bilateral sensorineural hearing loss. Speech and/or motor delay reported in these cases were attributed to the hearing impairment/vestibular arreflexia (cognitive abilities not tested).

SLC12A2 encodes sodium-potassium-chloride transporter 1 (also NKCC1).

The GTEx project has identified 8 isoforms. In brain both exon 21-containing/deleted isoforms are expressed (cited Morita et al 2014 - PMID: 24695712). As the authors discuss, RNA-seq of the developing mouse cochlea suggests that the exon 21 containing isoform is the single transcript expressed. Evidence from RNA-seq data (BrainSpan project) and literature suggests that the significant amounts of exon 21 lacking isoforms in fetal brain compensate for the deleterious effects of exon 21 variants and explain the lack of NDD in relevant patients.

Slc12a2 (NKCC1) null mouse model has demonstrated that the transporter plays a role in accumulation of the potassium rich endolymph in the inner ear, with NKCC1 absence causing sensorineural deafness and imbalance. Slc12a2 display cochlear malformations, loss of hair cells and hearing impairment (cited Delpire et al 1999 - PMID: 10369265). The brain phenotype has not been studied extensively, although loss of Slc12a2 has been shown to inhibit neurogenesis (cited: Magalhães and Rivera et al. - PMID: 27582690).

Slc12a2 null zebrafish display a collapse of the otic vesicle and reduced endolymph (Abbas and Whitfield, 2009 - PMID: 19633174) relevant to the human hearing disorder.

In vitro assessment of NKCC1 ion transporter function in Xenopus laevis, supported the deleterious effect of the identified variants (significant reduction in K+ influx). Using available single cell RNA-seq data the authors further demonstrated that SLC12A2 expressing cells display transcriptomic profiles reflective of active neurogenesis.

► Delpire et al (2016 - PMID: 27900370 - not reviewed in detail) described a 13 y.o. girl harboring a de novo 11-bp deletion in SLC12A2 exon 22. This individual reached developmental milestones on time and had a NORMAL cognitive function. Hearing was seemingly normal. Features included orthostatic intolerance, respiratory weakness, multiple endocrine abnormalities, pancreatic insufficiency and multiorgan failure incl. gut and bladder. Exome in the proband, parents and 3 unaffected sibs suggested SLC12A2 as the only candidate for her phenotype. Functional analyses in Xenopus laevis oocytes suggested that a non functional transporter was expressed and trafficked to the membrane as the wt. Detection of the truncated protein at higher molecular sizes suggested either enhanced dimerization or misfolded aggregate. There was no dominant-negative effect of mutant NKCC1. In patient fibroblasts a reduced total and NKCC1-mediated K+ influx.

► Mutai et al (2020 - PMID: 32294086) report on several individuals from 4 families, harboring variants within exon 21 or - in one case - at it's 3' splice-site (leading to skipping oe this exon at the mRNA level). All subjects were investigated for severe/profound hearing loss (in line with the role of exon 21-included isoforms in cochlea. The variant segregated with hearing impairment in 3 generations of a family while in all other subjects the variant had occured as de novo event. Despite motor delays (e.g. the subject from fam2 could not hold head or sit at the age of 10m / the proband in Fam3 was able to hold his head and walk at 6 and 20 m respectively) behavior and cognition were commented to be within normal range.


-----

Biallelic SLC12A2 mutations:

► Anazi et al (2017 - PMID: 29288388) briefly reported on a 3 y.o. boy (17DG0776) with central hypotonia, neonatal respiratory distress, failure to thrive, global DD and microcephaly and a skeletal survey suggestive of osteopenia. After non-diagnostic prior investigations (CMA revealing a 1p duplication classified as VUS, extensive metabolic workup), WES revealed a homozygous SLC12A2 splicing variant [NM_001046.2:c.2617-2A>G].

► Macnamara et al (2019 - PMID: 30740830) described a 5.5 y.o. male with sensorineural hearing loss, profound delays in all developmental areas among several other features (choanal atresia, failure to thrive, respiratory problems, absent sweat and tear production or salivation, GI abnormalities). Genetic testing for several disorders considered (cystic fibrosis, spinal muscular atrophy, sequencing and del/dup analysis of mtDNA) was normal. CMA revealed paternal uniparental isodisomy for chr. 5 and WGS a homozygous 22kb deletion in SLC12A2. This was followed by confirmation of homozygosity in the proband, heterozygosity of the unaffected father, delineation of breakpoints (chr5:127441491-127471419). mRNA studies in patient fibroblasts confirmed deletion of ex2-7, splicing of ex1 directly to ex8 and introduction of a premature stop codon in ex9. qRT-PCR confirmed that mRNA is likely subjected to NMD (expression ~80% of control). Western blot confirmed absence of the protein in the patient's fibroblasts. Again mouse models are thought to recapitulate the hearing defect but also the deficient saliva production (cited Evans et al 2000 - PMID: 10831596). Again the authors speculate a role of SLC12A2 in brain development based on evidence from murine models (migration, dendritic growth, increse in neuron density through regulation of GABAergic signalling (Young et al 2012 - PMID: 23015452). Hypotheses are also made on a regulatory relationship between NKCC1 and CFTR based on mRNA data from the ko mouse model.

► Stödberg et al (2020 - PMID: 32754646) reported 2 sibs with a complex neurodevelopmental disorder due to compound heterozygosity for a frameshift SLC12A2 variant and a splicing one (NM_001046:c.1431delT and c.2006-1G>A). Both presented hypotonia, neonatal S. aureus parotitis and respiratory problems (incl. apneas). While the older sib died at the age of 22 days, the younger one had persistent respiratory issues incl. a dry respiratory mucosa motivating metabolic, immunology investigations and testing for CF. She displayed microcephaly (OFC -2.5 SD, H was also -3.5SD), severe intellectual disability. MRI was suggestive of white matter and basal ganglia abnormalities. Other features incl. hearing impairment, and lack of tears,saliva and sweat, constipation and intestinal malrotation. There was facial dysmorphism. The variants were the only retained following WGS of the 2 affected sisters, parents and an unaffected brother. The splicing variant was shown to result in skipping of exon 13, while the indel in NMD. Again the authors discuss that the deficient saliva production, impaired hearing and GI problems are recapitulated in the mouse model (several refs provided).; Changed rating: GREEN; Changed publications: 28135719, 32658972, 27900370, 32294086, 29288388, 30740830, 32754646; Changed phenotypes: Kilquist syndrome, deafness, intellectual disability, dysmorphic features, absent salivation, ectodermal dysplasia, constipation, intestinal malrotation, multiple congenital anomalies; Changed mode of inheritance: BOTH monoallelic and biallelic, autosomal or pseudoautosomal
Mendeliome v0.2715 NID1 Zornitza Stark Phenotypes for gene: NID1 were changed from to Dandy-Walker malformation and occipital cephalocele; Hydrocephalus with or without seizures
Mendeliome v0.2712 NID1 Zornitza Stark reviewed gene: NID1: Rating: GREEN; Mode of pathogenicity: None; Publications: 23674478, 25558065, 12480912, 30773799; Phenotypes: Dandy-Walker malformation and occipital cephalocele, Hydrocephalus with or without seizures; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Mendeliome v0.2620 GALM Hazel Phillimore gene: GALM was added
gene: GALM was added to Mendeliome. Sources: Literature
Mode of inheritance for gene: GALM was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: GALM were set to PMID: 30451973; 30910422
Phenotypes for gene: GALM were set to galactosaemia; type IV galactosaemia
Review for gene: GALM was set to GREEN
Added comment: Homozygous and compound heterozygous variants (missense, nonsense and frameshift) found in 8 Japanese patients from unrelated families with unexplained galactosaemia. (No variants in GALT, GALK1, and GALE). This is therefore type IV galactosaemia.
In vitro expression analysis and enzyme activity assay of the patients’ peripheral blood mononuclear cells showed total lack of or compromised expression of GALM protein. Loss-of-function mechanism. One homozygote for one of these variants p.(Gly142Arg) in gnomAD (African population). (Wada, Y. et al 2019; PMID: 30451973)
In vitro expression assay and an enzyme activity assay of 67 GALM variants, taken from ExAc database (missense, nonsense, frameshift and splice). 30 variants concluded to be pathogenic due to no protein expression or faint expression. 5 variants with mildly lower levels were determined as likely pathogenic. All concluded to be loss-of-function mechanism. Incidence of galactosaemia by GALM deficiency is comparable to that of other galactosaemias. Carrier frequency and incidence was estimated for different populations. (Iwasawa, S. et al. (2019); PMID: 30910422)
Sources: Literature
Mendeliome v0.2339 DAG1 Zornitza Stark Phenotypes for gene: DAG1 were changed from to Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 9; Muscular dystrophy-dystroglycanopathy (limb-girdle), type C, 9, 613818; Walker-Warburg syndrome and tectocerebellar dysgraphia
Mendeliome v0.2302 TRPC3 Bryony Thompson gene: TRPC3 was added
gene: TRPC3 was added to Mendeliome. Sources: Expert list
Mode of inheritance for gene: TRPC3 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted
Publications for gene: TRPC3 were set to 25477146; 19351902
Phenotypes for gene: TRPC3 were set to Spinocerebellar ataxia 41 MIM#616410
Mode of pathogenicity for gene: TRPC3 was set to Other
Review for gene: TRPC3 was set to AMBER
Added comment: A heterozygous gain-of function missense has been identified in a 40-year-old man with adult-onset spinocerebellar ataxia. A mouse model of dominant cerebellar ataxia, termed 'moonwalker', contains a gain-of-function variant in this gene.
Sources: Expert list
Mendeliome v0.2301 DAG1 Elena Savva reviewed gene: DAG1: Rating: GREEN; Mode of pathogenicity: None; Publications: PMID: 29337005, 25503980; Phenotypes: Muscular dystrophy-dystroglycanopathy (congenital with brain and eye anomalies), type A, 9, Muscular dystrophy-dystroglycanopathy (limb-girdle), type C, 9, 613818, Walker-Warburg syndrome and tectocerebellar dysgraphia; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Mendeliome v0.1683 RSPRY1 Zornitza Stark Phenotypes for gene: RSPRY1 were changed from to Spondyloepimetaphyseal dysplasia, Faden-Alkuraya type, 616585
Mendeliome v0.1679 RSPRY1 Zornitza Stark reviewed gene: RSPRY1: Rating: AMBER; Mode of pathogenicity: None; Publications: 26365341; Phenotypes: Spondyloepimetaphyseal dysplasia, Faden-Alkuraya type, 616585; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal
Mendeliome v0.1671 FUT2 Zornitza Stark Phenotypes for gene: FUT2 were changed from to [Bombay phenotype, digenic] 616754; {Norwalk virus infection, resistance to}; {Vitamin B12 plasma level QTL1} 612542
Mendeliome v0.1669 FUT2 Zornitza Stark reviewed gene: FUT2: Rating: RED; Mode of pathogenicity: None; Publications: ; Phenotypes: [Bombay phenotype, digenic] 616754, {Norwalk virus infection, resistance to}, {Vitamin B12 plasma level QTL1} 612542; Mode of inheritance: None
Mendeliome v0.1002 ALKBH8 Zornitza Stark Classified gene: ALKBH8 as Green List (high evidence)
Mendeliome v0.1002 ALKBH8 Zornitza Stark Gene: alkbh8 has been classified as Green List (High Evidence).
Mendeliome v0.912 DHPS Zornitza Stark gene: DHPS was added
gene: DHPS was added to Mendeliome. Sources: Expert list
Mode of inheritance for gene: DHPS was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: DHPS were set to 30661771
Phenotypes for gene: DHPS were set to Neurodevelopmental disorder with seizures and speech and walking impairment, MIM#618480
Review for gene: DHPS was set to GREEN
gene: DHPS was marked as current diagnostic
Added comment: 5 individuals from 4 unrelated families with biallelic pathogenic variants in DHPS, note one variant is recurrent (c.518A>G or p.Asn173Ser). The phenotype consisted of DD/ID (5/5), tone abnormalities (hypotonia/hypertonia/spasticity - 5/5), seizures (5/5 - in one case though unclear staring spells) with EEG abnormalities (5/5). Additionally most individuals displayed behavioral issues, or some common facial features
Sources: Expert list
Mendeliome v0.702 ALKBH8 Zornitza Stark Classified gene: ALKBH8 as Amber List (moderate evidence)
Mendeliome v0.702 ALKBH8 Zornitza Stark Gene: alkbh8 has been classified as Amber List (Moderate Evidence).
Mendeliome v0.391 EXOC3L2 Zornitza Stark Phenotypes for gene: EXOC3L2 were changed from to Dandy-Walker malformation; renal dysplasia; bone marrow failure
Mendeliome v0.223 ALKBH8 Zornitza Stark Marked gene: ALKBH8 as ready
Mendeliome v0.223 ALKBH8 Zornitza Stark Gene: alkbh8 has been classified as Green List (High Evidence).
Mendeliome v0.223 ALKBH8 Zornitza Stark Classified gene: ALKBH8 as Green List (high evidence)
Mendeliome v0.223 ALKBH8 Zornitza Stark Gene: alkbh8 has been classified as Green List (High Evidence).
Mendeliome v0.222 ALKBH8 Zornitza Stark gene: ALKBH8 was added
gene: ALKBH8 was added to Mendeliome_VCGS. Sources: Literature
Mode of inheritance for gene: ALKBH8 was set to BIALLELIC, autosomal or pseudoautosomal
Publications for gene: ALKBH8 were set to 31079898
Phenotypes for gene: ALKBH8 were set to Intellectual developmental disorder, autosomal recessive 71, MIM#618504
Review for gene: ALKBH8 was set to GREEN
Added comment: Two families and functional data.
Sources: Literature
Mendeliome v0.0 GALK1 Zornitza Stark gene: GALK1 was added
gene: GALK1 was added to Mendeliome_VCGS. Sources: Expert Review Green,Victorian Clinical Genetics Services
Mode of inheritance for gene: GALK1 was set to Unknown
Mendeliome v0.0 ALK Zornitza Stark gene: ALK was added
gene: ALK was added to Mendeliome_VCGS. Sources: Expert Review Green,Victorian Clinical Genetics Services
Mode of inheritance for gene: ALK was set to Unknown