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| Intellectual disability syndromic and non-syndromic v0.6030 | ANO4 |
Ain Roesley gene: ANO4 was added gene: ANO4 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ANO4 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: ANO4 were set to 38744284 Phenotypes for gene: ANO4 were set to neurodevelopmental disorder MONDO:0700092, ANO4-related Review for gene: ANO4 was set to GREEN gene: ANO4 was marked as current diagnostic Added comment: aka TMEM16D 5x de novo + 2x inherited missense (73% penetrance + asymptomatic) the ones with de novo variants: all had ID, hypotonia 4x skeletal features (scoliosis, funnel chest, pet plants, hyper extensible joints) all had epilepsy all had abnormal MRI Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5782 | PTRH2 | Bryony Thompson reviewed gene: PTRH2: Rating: GREEN; Mode of pathogenicity: None; Publications: 33092935, 37239392; Phenotypes: neurologic, endocrine, and pancreatic disease, multisystem, infantile-onset 1 MONDO:8000012; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5743 | KCNB2 |
Ain Roesley gene: KCNB2 was added gene: KCNB2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: KCNB2 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: KCNB2 were set to 38503299 Phenotypes for gene: KCNB2 were set to neurodevelopmental disorder MONDO:0700092, KCNB2-related Review for gene: KCNB2 was set to GREEN gene: KCNB2 was marked as current diagnostic Added comment: 7 individuals, all missense 5 de novo + 1x inherited from father who has hypotonia + 1x from asymptomatic father 2/5 MRI anomalies 2/5 cardiac anomalies 2/7 urogenital anomalies 7/7 with ID 2/7 epilepsy 2/7 hypotonia Sources: Literature Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5631 | SV2A |
Karina Sandoval gene: SV2A was added gene: SV2A was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: SV2A was set to BOTH monoallelic and biallelic (but BIALLELIC mutations cause a more SEVERE disease form), autosomal or pseudoautosomal Publications for gene: SV2A were set to PMID: 37985816 Phenotypes for gene: SV2A were set to Epilepsy, MONDO:0005027; microcephaly MONDO:0001149; intellectual disability MONDO:0001071 Review for gene: SV2A was set to AMBER Added comment: Monoallelic variants cause epilepsy. Biallelic variant in this 5yo with p.Arg289Ter and another 5yo from another paper with homozygous p.Arg383Gln, reported to cause severe phenotype of drug-resistant epileptic encephalopathy with microcephaly, DD, movement disorder and growth retardation. This paper references 5 other families with both AR & AD Family #1 – p.Arg383Gln, AR, 2 affected in family, parents healthy carriers Family #2 – p.Arg570Cys, AD, 2 affected, inherited from affected mother (in gnomAD v2 1 het, absent from gnomAD v3) Family #3 – p.Gly660Arg, AD, de novo Family #4 – p.Gly660Arg, AD, segregated in 11 family members Family #5 (this study) – p.Arg289Ter, AR, parents and 2 sibs asymptomatic carriers Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5627 | SEL1L |
Sarah Pantaleo gene: SEL1L was added gene: SEL1L was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: SEL1L was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: SEL1L were set to PMID: 37943610; PMID: 37943617 Phenotypes for gene: SEL1L were set to Neurodevelopmental disorder, MONDO:0700092, SEL1L-related Penetrance for gene: SEL1L were set to Complete Review for gene: SEL1L was set to GREEN Added comment: Wang paper PMID: 37943610 SEL1L protein is involved in the SEL1L-HRD1 endoplasmic reticulum (ER)-associated degradation. Report two biallelic missense variants in SEL1L in six children from three independent families presenting with developmental delay, intellectual disability, microcephaly, facial dysmorphisms, hypotonia and/or ataxia (termed ERAD-associated neurodevelopment disorder with onset in infancy (ENDI). The variants were hypomorphic and impaired ERAD function. Identified by WES. Parents heterozygous and asymptomatic. P.(Gly585Asp) in Patient 1, p.(Met528Arg) in Patients 2 and 3 (siblings). All variants cause substrate accumulation. The extent of substrate accumulation in knockin cells was modest compared to those in knockout cells, pointing to a hypomorphic nature. They also had a variant in HRD1. Weis paper PMID: 37943617 Third variant p.(Cys141Tyr), biallelic, causing premature death in five patients from a consanguineous family with early-onset neurodevelopmental disorders and agammaglobulinaemia due to severe SEL1L-HRD1 ERAD dysfunction. This variant appears to have a more severe outcome, exhibiting B cell depletion and agammaglobulinaemia, causing the most severe dysfunction among all of the variants described by this group so far. They postulate that functionality of SEL1L-HRD1 ERAD is inversely correlated with disease severity in humans. Their symptoms were dev delay, neurological disorder and agammaglobulinaemia in childhood. Along with severe axial hypotonia, short stature and microcephaly. “Not a complete loss-of-function variant”. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5598 | ELP1 |
Sarah Pantaleo gene: ELP1 was added gene: ELP1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ELP1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: ELP1 were set to PMID: 36864284 Phenotypes for gene: ELP1 were set to Neurodevelopmental disorder, MONDO:0700092, ELP1-related Review for gene: ELP1 was set to RED Added comment: “A novel ELP1 mutation impairs the function of the Elongator complex and causes a severe neurodevelopment disorder”. The Elongator complex is suggested to play a role in NDDs, given that patient-derived mutations in its ELP2, ELP3, ELP4 and ELP6 subunits have been associated with these disorders. Pathogenic variants in ELP1 have been previously found in familial dysautonomia and medulloblastoma, with no link to NDDs affecting primarily the central nervous system. Clinical investigation included patient history and physical, neurological and MRI. A novel homozygous likely pathogenic ELP1 variant was identified by WGS (absent from gnomAD). Functional studies included in silico analysis of the mutated ELP1 in the context of the holo-complex, production and purification of the ELP1 harbouring the identified mutation and in vitro analyses. Report a novel missense mutation in the ELP1 identified in two siblings with ID and GDD (both less than 10 years old). The mutation is shown to perturb the ability of ELP123 to bind tRNAs and compromises the function of the Elongator in vitro and in human cells. Both sibling are non-verbal and had severe ID/GDD. MRI revealed white matter lesions with enlarged perivascular spaces, suggestive of an inflammatory reaction associate with demyelination. WGS identified c.2444A>C; p.(Lys815Thr), homozygous in both siblings. Consanguineous family. Parents heterozygous and asymptomatic. Carry out significant functional studies. Conclude that screening for ELP1 mutations “may be beneficial”. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5399 | PTEN | Claire Fryer-Smith reviewed gene: PTEN: Rating: GREEN; Mode of pathogenicity: None; Publications: 21194675, 1859181, 23470840; Phenotypes: Cowden syndrome 1 MIM#158350, Lhermitte-Duclos disease MIM#158350, Macrocephaly/autism syndrome MIM#605309, Prostate cancer, somatic MIM#176807; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5399 | SMAD4 | Claire Fryer-Smith reviewed gene: SMAD4: Rating: GREEN; Mode of pathogenicity: None; Publications: 9843046, 22243968, 7296942, 8261650; Phenotypes: Juvenile polyposis/hereditary hemorrhagic telangiectasia syndrome MIM#175050, Myhre syndrome MIM#139210, Pancreatic cancer, somatic MIM#260350, Polyposis, juvenile intestinal MIM#174900; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5177 | ATG4D |
Suliman Khan gene: ATG4D was added gene: ATG4D was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ATG4D was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: ATG4D were set to PMID: 36765070 Phenotypes for gene: ATG4D were set to neurodevelopmental disorder; Abnormal facial shape Penetrance for gene: ATG4D were set to unknown Review for gene: ATG4D was set to GREEN Added comment: PMID: 36765070 reported three individuals from two unrelated families with a neurodevelopmental disorder characterized by speech and motor impairment with a similar facial gestalt comprising almond-shaped eyes, depressed nasal bridge, and a prominent Cupid’s bow with variable disease severity and progression. NGS analysis revealed bi-allelic loss-of-function variants in ATG4D gene. Based on the clinical, bioinformatic, and functional data, the author concluded that bi-allelic loss-of-function variants in ATG4D contribute to the pathogenesis of syndromic neurodevelopmental disorder. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5148 | TRPC5 |
Zornitza Stark gene: TRPC5 was added gene: TRPC5 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: TRPC5 was set to X-LINKED: hemizygous mutation in males, biallelic mutations in females Publications for gene: TRPC5 were set to 36323681; 24817631; 23033978; 33504798; 28191890 Phenotypes for gene: TRPC5 were set to Neurodevelopmental disorder, MONDO:0700092, TRPC5-related Review for gene: TRPC5 was set to AMBER Added comment: PMID: 36323681; Leitão E. et al. (2022) Nat Commun.13(1):6570: Missense variant NM_012471.2:c.523C>T, p.(Arg175Cys in three brothers with intellectual disability (ID) and autistic spectrum disorder (ASD), inherited from an asymptomatic mother and absent in the maternal grandparents. Whole cell patch clamp studies of HEK293 created by site-directed mutagenesis showed increased current of this calcium channel (constitutively opened). (This variant is absent in gnomAD v2.1.1). Also, the nonsense variant, c.965G> A, p.(Trp322*) was found in a high functioning ASD male (maternally inherited), NMD-predicted. Other papers and TRPC5 variants that were cited to associate this gene with X-linked ID and/or ASD include: PMID: 24817631; Mignon-Ravix, C. et al. (2014) Am. J.Med. Genet. A 164A: 1991–1997: A hemizygous 47-kb deletion in Xq23 including exon 1 of the TRPC5 gene. He had macrocephaly, delayed psychomotor development, speech delay, behavioural problems, and autistic features. Maternally inherited, and a family history compatible with X-linked inheritance (i.e., maternal great uncle was also affected, although not tested). In addition, PMID: 36323681; Leitão E. et al. (2022) cites papers with the variants p.(Pro667Thr), p.(Arg71Gln) and p.(Trp225*). NB. p.(Pro667Thr) is absent in gnomAD (v2.1.1), p.(Arg71Gln) is also absent (the alternative variant p.(Arg71Trp) is present once as heterozygous only). p.(Trp225*) is absent, and it should be noted that PTCs / LoF variants are very rare (pLI = 1). However, looking further into the three references, the evidence is not as clear or as accurate as was stated. The missense variant c.1999C>A, p.(Pro667Thr), was stated as de novo, but was actually maternally inherited but was still considered a candidate for severe intellectual disability (shown in the Appendix, Patient 93, with severe speech delay, autism spectrum disorder and Gilles de la Tourette). This patient also has a de novo MTF1 variant. Reference: PMID: 23033978; de Ligt, J. et al. (2012) N. Engl. J. Med. 367: 1921–1929). Missense variant (de novo): c.212G>A, p.(Arg71Gln), was found as part of the Deciphering Developmental Disorders (DDD) study and is shown in individual 164 in Supplementary Table 2 of PMID: 33504798; Martin, HC. et al. (2021) Nat. Commun.12: 627. Also displayed in DECIPHER (DDD research variant) with several phenotype traits, but ID and ASD are not specifically mentioned. Nonsense variant: c.674G>A. p.(Trp225*) was stated as de novo but was inherited (reference PMID: 28191890; Kosmicki, JA. et al. (2017) Nat. Genet. 49: 504–510. Supplement Table 7). This was a study of severe intellectual delay, developmental delay / autism. (NB. The de novo p.(Arg71Gln) variant from the DDD study is also listed (subject DDD 342 in Supplement 4 / Table 2). Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.5079 | DLD | Philip Adam Harraka reviewed gene: DLD: Rating: GREEN; Mode of pathogenicity: None; Publications: 34745891, 33092611, 8968745; Phenotypes: Dihydrolipoamide dehydrogenase deficiency, hepatic and neurological disease; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5079 | ALMS1 | Christa Whelan reviewed gene: ALMS1: Rating: RED; Mode of pathogenicity: None; Publications: MIM # 203800, 27142762, 25846608, 18154657, 25296579, 17146208, 17940554, 22043170, 31889847, 2231654, 8418611, 8181924, 8556827, 9663233, 25864795, 8556827, 11941369.; Phenotypes: Alström Syndrome (multisystemic), characterized by progressive cone-rod dystrophy leading to blindness, sensorineural hearing loss, childhood obesity associated with hyperinsulinemia, and type 2 diabetes mellitus, Dilated cardiomyopathy occurs in approximately 70% of patients during infancy or adolescence, Renal failure, pulmonary, hepatic, and urologic dysfunction are often observed, and systemic fibrosis develops with age MIM# 203800; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5053 | GABRA3 |
Sarah Pantaleo gene: GABRA3 was added gene: GABRA3 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: GABRA3 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: GABRA3 were set to PMID: 29053855 Phenotypes for gene: GABRA3 were set to Epilepsy, intellectual disability, dysmorphic features, Penetrance for gene: GABRA3 were set to Incomplete Review for gene: GABRA3 was set to GREEN Added comment: Six variants in GABRA3 encoding the alpha3-subunit of the GABA(A) receptor. Five missense variants and one micro duplication were detected in four families and two sporadic cases presenting with a range of epileptic seizure types, a varying degree of intellectual disability and developmental delay, sometimes with dysmorphic features or nystagmus. The variants co-segregated mostly but not completely with the phenotype in the families, indicating in some cases incomplete penetrance, involvement of other genes, or presence of phenocopies. Overall, males were more severely affected and there were three asymptomatic female mutation carriers compared to only one male without a clinical phenotype. Mechanism suggested - three detected missense variants are localised in the extracellular GABA-binding NH2-terminus, one in the M2-M3 linker and one in the M4 transmembrane segment of the alpha3-subunit. Functional studies in Xenopus leaves oocytes revealed a variable but significant reduction of GABA-evoked anion currents for all mutants compared to wild-type receptors. The degree of current reduction correlated partially with the phenotype. Results reveal that rare loss-of-function variants in GABRA3 increase the risk for a varying combination of epilepsy, intellectual disability/developmental delay and dysmorphic features, presenting in some pedigrees with an X-linked inheritance pattern. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.4946 | ARSA | Zornitza Stark Phenotypes for gene: ARSA were changed from to Metachromatic leukodystrophy, MIM# 250100 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4944 | ARSA | Zornitza Stark reviewed gene: ARSA: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: Metachromatic leukodystrophy, MIM# 250100; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4774 | MTOR | Zornitza Stark Phenotypes for gene: MTOR were changed from to Smith-Kingsmore syndrome, MIM# 616638; Focal cortical dysplasia, type II, somatic, MIM# 607341; Overgrowth syndrome and/or cerebral malformations due to abnormalities in MTOR pathway genes, MONDO:0100283 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4770 | MTOR | Zornitza Stark reviewed gene: MTOR: Rating: GREEN; Mode of pathogenicity: Other; Publications: 28892148, 25878179, 26018084; Phenotypes: Smith-Kingsmore syndrome, MIM# 616638, Focal cortical dysplasia, type II, somatic, MIM# 607341, Overgrowth syndrome and/or cerebral malformations due to abnormalities in MTOR pathway genes, MONDO:0100283; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4687 | GLRA2 |
Zornitza Stark gene: GLRA2 was added gene: GLRA2 was added to Intellectual disability syndromic and non-syndromic. Sources: Expert list Mode of inheritance for gene: GLRA2 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: GLRA2 were set to 26370147; 20479760; 35294868 Phenotypes for gene: GLRA2 were set to Intellectual developmental disorder, X-linked, syndromic, Pilorge type, MIM# 301076 Review for gene: GLRA2 was set to GREEN Added comment: More than 10 unrelated families reported. Both males and females affected, though some mothers are asymptomatic or mild. Zebrafish model. Sources: Expert list |
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| Intellectual disability syndromic and non-syndromic v0.4484 | ITSN1 |
Ee Ming Wong changed review comment from: -10 individuals from eight unrelated with neurodevelopmental disorder spectrum including ASD, ID, major behavioral difficulties and/or verbal impairment. -variants included heterozygous premature truncating and missense variants -Majority of variants were de novo; in two patients the reported variant was inherited from paucisymptomatic father Sources: Literature; to: -10 individuals from eight unrelated families with neurodevelopmental disorder spectrum including ASD, ID, major behavioral difficulties and/or verbal impairment. -variants included heterozygous premature truncating and missense variants -Majority of variants were de novo; in two patients the reported variant was inherited from paucisymptomatic father Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.4484 | ITSN1 |
Ee Ming Wong gene: ITSN1 was added gene: ITSN1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: ITSN1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: ITSN1 were set to PMID: 34707297 Phenotypes for gene: ITSN1 were set to neurodevelopmental disorder MONDO:0700092 ITSN1-related Penetrance for gene: ITSN1 were set to unknown gene: ITSN1 was marked as current diagnostic Added comment: -10 individuals from eight unrelated with neurodevelopmental disorder spectrum including ASD, ID, major behavioral difficulties and/or verbal impairment. -variants included heterozygous premature truncating and missense variants -Majority of variants were de novo; in two patients the reported variant was inherited from paucisymptomatic father Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.4435 | RNF220 | Zornitza Stark Phenotypes for gene: RNF220 were changed from Leukodystrophy; CNS hypomyelination; Ataxia; Intellectual disability; Sensorineural hearing impairment; Elevated hepatic transaminases; Hepatic fibrosis; Dilated cardiomyopathy; Spastic paraplegia; Dysarthria; Abnormality of the corpus callosum to Leukodystrophy, hypomyelinating, 23, with ataxia, deafness, liver dysfunction, and dilated cardiomyopathy, MIM# 619688; Leukodystrophy; CNS hypomyelination; Ataxia; Intellectual disability; Sensorineural hearing impairment; Elevated hepatic transaminases; Hepatic fibrosis; Dilated cardiomyopathy; Spastic paraplegia; Dysarthria; Abnormality of the corpus callosum | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4434 | RNF220 | Zornitza Stark reviewed gene: RNF220: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: Leukodystrophy, hypomyelinating, 23, with ataxia, deafness, liver dysfunction, and dilated cardiomyopathy, MIM# 619688, Leukodystrophy, CNS hypomyelination, Ataxia, Intellectual disability, Sensorineural hearing impairment, Elevated hepatic transaminases, Hepatic fibrosis, Dilated cardiomyopathy, Spastic paraplegia, Dysarthria, Abnormality of the corpus callosum; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4422 | VPS50 | Zornitza Stark Phenotypes for gene: VPS50 were changed from Neonatal cholestatic liver disease; Failure to thrive; Profound global developmental delay; Postnatal microcephaly; Seizures; Abnormality of the corpus callosum to Neurodevelopmental disorder with microcephaly, seizures, and neonatal cholestasis , MIM#619685; Neonatal cholestatic liver disease; Failure to thrive; Profound global developmental delay; Postnatal microcephaly; Seizures; Abnormality of the corpus callosum | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4370 | KCND2 |
Zornitza Stark gene: KCND2 was added gene: KCND2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: KCND2 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: KCND2 were set to 24501278; 16934482; 29581270; 34245260 Phenotypes for gene: KCND2 were set to Neurodevelopmental disorder MONDO:0700092; global developmental delay, HP:0001263; seizure, HP:0001250 Review for gene: KCND2 was set to GREEN Added comment: 6 new unrelated cases with developmental delay reported in PMID: 34245260 (Zhang et al 2021), 3 of whom had seizures. All had heterozygous missense variants of KCND2 in sites known to be critical for channel gating (E323K, P403A, two individuals, V404L, two individuals and V404M). Functional studies suggest that these missense changes cause both a partial loss-of-function (LOF) and gain-of-function (GOF). The V404 change appears to increase epileptic seizure susceptibility with the 3 patients with a V404 change showing this phenotype. PMID:24501278 - Lee et al, 2014 - reports pair of monozygotic twin boys with infantile onset severe refractory epilepsy and autism. A de novo heterozygous missense variant was identified by WES - V404M. PMID: 29581270 - Lin et al, 2018 - performed functional work that shows V404M enhances inactivation of channels that have not yet opened and dramatically impairs the inactivation of channels that have opened. PMID:16934482 - Singh et al, 2006 - reports a patient with cognative impairment who also went on to have seizures starting from age 13 with a 5 bp deletion in KCND2 leading to premature stop codon. The proband's asymptomatic father also shared this variant. Sources: Literature Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.4358 | ADCY5 |
Zornitza Stark changed review comment from: Variants in this gene cause a movement disorder, intellectual disability is not typically a feature. Note one report of two siblings with bi-allelic variants and much more severe phenotype including ID (PMID 33704598); however parents were asymptomatic so evidence for causality is limited.; to: Mono-allelic variants in this gene also cause a movement disorder, intellectual disability is not typically a feature. Note also reports of a milder AR condition causing a movement disorder, where ID is not a feature. |
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| Intellectual disability syndromic and non-syndromic v0.4255 | MYH10 |
Krithika Murali gene: MYH10 was added gene: MYH10 was added to Intellectual disability syndromic and non-syndromic. Sources: Expert list,Literature Mode of inheritance for gene: MYH10 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: MYH10 were set to 24825879; 24901346; 25356899; 22495309; 25003005 Phenotypes for gene: MYH10 were set to Microcephaly; Intellectual Disability Review for gene: MYH10 was set to GREEN Added comment: De novo variants were identified in 5 unrelated individuals with moderate-severe ID and developmental delay. Other reported phenotypic features include microcephaly (4/5), IUGR/failure to thrive (4/5), cerebral atrophy (3/5), hydrocephalus (2/5), congenital bilateral hip dysplasia (2/5), cerebellar atrophy (1/5), congenital diaphragmatic hernia (1/5), cranial nerve palsy (1/5), nystagmus (1/5), dysplastic kidney (1/5). Defects in heart development, body wall closure and other birth defects noted in mouse models. Sources: Expert list, Literature |
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| Intellectual disability syndromic and non-syndromic v0.4161 | SARS |
Bryony Thompson gene: SARS was added gene: SARS was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: SARS was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: SARS were set to 28236339; 34570399 Phenotypes for gene: SARS were set to Intellectual disability Review for gene: SARS was set to AMBER Added comment: Summary - 2 unrelated families with overlapping ID phenotype, and supporting in vitro and patient cell assays. PMID: 28236339 - an Iranian family (distantly related) segregating a homozygous missense (c.514G>A, p.Asp172Asn) with moderate ID, microcephaly, ataxia, speech impairment, and aggressive behaviour. Also, supporting in vitro functional assays demonstrating altered protein function. PMID: 34570399 - a consanguineous Turkish family segregating a homozygous missense (c.638G>T, p.(Arg213Leu)) with developmental delay, central deafness, cardiomyopathy, and metabolic decompensation during fever leading to death. Also, reduced protein level and enzymatic activity in patient cells. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.4059 | RNF220 |
Konstantinos Varvagiannis gene: RNF220 was added gene: RNF220 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature,Other Mode of inheritance for gene: RNF220 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: RNF220 were set to 33964137; 10881263 Phenotypes for gene: RNF220 were set to Leukodystrophy; CNS hypomyelination; Ataxia; Intellectual disability; Sensorineural hearing impairment; Elevated hepatic transaminases; Hepatic fibrosis; Dilated cardiomyopathy; Spastic paraplegia; Dysarthria; Abnormality of the corpus callosum Penetrance for gene: RNF220 were set to Complete Review for gene: RNF220 was set to GREEN Added comment: Sferra et al (2021 - PMID: 33964137) provide extensive evidence that biallelic RNF220 mutations cause a disorder characterized by hypomyelinating leukodystrophy, ataxia (9/9 - onset 1-5y), borderline intellectual functioning (3/9) / intellectual disability (5/9 - in most cases mild), sensorineural deafness (9/9) with complete hearing loss in the first decade of life, hepatopathy (9/9) with associated periportal fibrosis, and dilated cardiomyopathy (9/9) which was fatal. Other neurologic manifestations apart from ataxia incl. hyperreflexia (8/8), spastic paraplegia (9/9), dysarthria (9/9), peripheral neuropathy (4/9), seizures in one case (1/9). Upon brain MRI there was thin corpus callosum (9/9) or cerebellar atrophy in some (2/9). The authors identified homozygosity for 2 recurrent missense RNF220 variants in affected members belonging to these 5 broad consanguineous pedigrees (7 families), namely NM_018150.4:c.1094G>A / p.Arg365Gly in 4 Roma families in the context of a shared haplotype (/founder effect) as well as c.1088G>A / p.Arg363Gly in a large pedigree from southern Italy initially reported by Leuzzi et al (2000 - PMID: 10881263). Extensive segregation analyses were carried out including several affected and unaffected members. RNF220 encodes ring finger protein 220, which functions as an E3 ubiquitin ligase. Previous studies have shown among others a role in modulation of Sonic hedgehog/GLI signaling and cerebellar development Evidence for the role of RNF220 included relevant expression, localization within the cell, interaction partners (lamin B1, 20S proteasome), similarities with other laminopathies in terms of phenotype, etc : *RNF220 has a relevant expression pattern in CNS (based on qRT-PCR analyses in human brain, cerebellum, cerebral cortex / mRNA levels in human fetal CNS with higher expression in cerebellum, spinal cord and cortex / previous GTEx data / protein levels in mouse CNS) *The protein displays nuclear localization based on iPSC cells differentiated to motor neurons (also supported by data from the Human Protein Atlas). Transfection of COS-1 cells demonstrated localization primarily to the nucleus (as also previously demonstrated in HEK293T cells) in vesicle like structures with ASF2/SF2 colocalization suggesting enrichment in nuclear speckles. There was also partial co-distribution with the 20S proteasome. R363Q and R365Q additionally coalesced in the cytoplasm forming protein aggregates/inclusions. *Immunofluorescence studies in patient fibroblasts also confirmed abnormal increase of the protein in the cytoplasm and increased fluorescence with the 20S proteasome. *Proteomic identification of RNF220-interacting proteins in transfected HEK293T cells demonstrated enrichment for all members of the lamin protein family (incl . lamin B1, AC, B2). *RNAi-mediated downregulation of RNF222 in Drosophila suggested altered subcellular localization and accumulation of the fly orthologue for human lamin B1. *Immunoprecipitation of lamin B1 from the nuclear matrix of cerebellar cells suggested significant interaction of endogenous lamin B1 with RNF220, while transfection studies in HEK293T cells for wt/mt suggested reduced binding to endogenous lamin B1 for RNF220 mt compared to wt (more prominent for R365Q). RNF220 mutants also reduced ubiquitination of nuclear lamin B1 compared to wt. *Patient fibroblasts immunostained with different nuclear envelope markers displayed abnormal nuclear shapes with multiple invaginations and lobulations, findings also observed in laminopathies. There is currently no associated phenotype in OMIM or G2P. SysID includes RNF220 among the current primary ID genes. Sources: Literature, Other |
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| 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 v0.4033 | UBR1 | Zornitza Stark changed review comment from: >50 unrelated families reported, reviewed in PMID: 24599544. Common clinical features include poor growth, mental retardation, and variable dysmorphic features, including aplasia or hypoplasia of the nasal alae, abnormal hair patterns or scalp defects, and oligodontia. Other features include hypothyroidism, sensorineural hearing loss, imperforate anus, and pancreatic exocrine insufficiency.; to: >50 unrelated families reported, reviewed in PMID: 24599544. Common clinical features include poor growth, intellectual disability, and variable dysmorphic features, including aplasia or hypoplasia of the nasal alae, abnormal hair patterns or scalp defects, and oligodontia. Other features include hypothyroidism, sensorineural hearing loss, imperforate anus, and pancreatic exocrine insufficiency. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4013 | EDEM3 |
Michelle Torres gene: EDEM3 was added gene: EDEM3 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: EDEM3 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: EDEM3 were set to 34143952 Phenotypes for gene: EDEM3 were set to EDEM3-congenital disorder of glycosylation Review for gene: EDEM3 was set to GREEN Added comment: PMID: 34143952: 7 families (11 individuals) with 6x PTV and 2x missense variants with neurodevelopmental delay and variable facial dysmorphisms. The unaffected parents were all heterozygous carriers. Functional show LoF of EDEM3 enzymatic activity. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.4002 | SYNCRIP |
Konstantinos Varvagiannis gene: SYNCRIP was added gene: SYNCRIP was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: SYNCRIP was set to MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown Publications for gene: SYNCRIP were set to 34157790; 30504930; 27479843; 23020937 Phenotypes for gene: SYNCRIP were set to Global developmental delay; Intellectual disability; Autism; Myoclonic atonic seizures; Abnormality of nervous system morphology Review for gene: SYNCRIP was set to AMBER Added comment: Semino et al (2021 - PMID: 34157790) provide clinical details on 3 unrelated individuals with de novo SYNCRIP variants and provide a review of 5 additional subjects previously identified within large cohorts in the literature and databases. Features included DD, ID (7/7 for whom this information was available), ASD or autistic features (4/7). MRI abnormalities were observed in 3 (widening of CSF spaces, periventricular nodular heterotopia, prominent lat. ventricles). Epilepsy (myoclonic-astatic epilepsy / Doose syndrome) was reported for 2(/8) individuals. The 3 patients here reported were identified following trio/singleton exome with Sanger confirmation of the variants and their de novo occurrence. Variants are in almost all cases de novo (7/7 for whom this was known) and in 5/8 cases were pLoF, in 2/8 missense SNVs while a case from DECIPHER had a 77.92 kb whole gene deletion not involving other genes with unknown inheritance. Overall the variants reported to date include [NM_006372.5]: 1 - c.858_859del p.(Gly287Leufs*5) 2 - c.854dupA p.(Asn285Lysfs*8) 3 - c.734T>C p.(Leu245Pro) 4 - chr6:85605276-85683190 deletion (GRCh38) 5 - c.629T>C p.(Phe210Ser) 6 - c.1573_1574delinsTT p.(Gln525Leu) 7 - c.1247_1250del p.(Arg416Lysfs*145) 8 - c.1518_1519insC p.(Ala507Argfs*14) [P1-3: this report, P4: DECIPHER 254774, P5-6: Guo et al 2019 - PMID: 30504930, P7: Lelieveld et al 2016 - PMID: 27479843, P8: Rauch et al 2012 - PMID: 23020937 / all other Refs not here reviewed, clinical details summarized by Semino et al in table 1] SYNCRIP (also known as HNRNPQ) encodes synaptotagmin‐binding cytoplasmic RNA‐interacting protein. As the authors note, this RNA-binding protein is involved in multiple pathways associated with neuronal/muscular developmental disorders. Several references are provided for its involvement in regulation of RNA metabolism, among others sequence recognition, pre-mRNA splicing, translation, transport and degradation. Mutations in other RNA-interacting proteins and hnRNP members (e.g. HNRNPU, HNRNPD) are associated with NDD. The missense variant (p.Leu245Pro) is within RRM2 one of the 3 RNA recognition motif (RRM) domains of the protein. These 3 domains, corresponding to the central part of the protein (aa 150-400), are relatively intolerant to variation (based on in silico predictions and/or variation in gnomAD). Leu245 localizes within an RNA binding pocket and in silico modeling suggests alteration of the tertiary structure and RNA-binding capacity of RRM2. There are no additional studies performed. Overall haploinsufficiency appears to be the underlying disease mechanism based on the truncating variants and the gene deletion. [pLI in gnomAD : 1, %HI : 2.48%] Animal models are not discussed. There is no associated phenotype in OMIM. This gene is included in the DD panel of G2P (monoallelic LoF variants / SYNCRIP-related developmental disorder). SysID also lists SYNCRIP within the current primary ID genes. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3973 | YARS | Zornitza Stark Phenotypes for gene: YARS were changed from Intellectual disability; deafness; nystagmus; liver dysfunction to Infantile-onset multisystem neurologic, endocrine, and pancreatic disease 2, MIM# 619418 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3972 | YARS | Zornitza Stark edited their review of gene: YARS: Changed phenotypes: Infantile-onset multisystem neurologic, endocrine, and pancreatic disease 2, MIM# 619418 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3718 | ADCY5 |
Zornitza Stark changed review comment from: Variants in this gene cause a movement disorder, intellectual disability is not typically a feature.; to: Variants in this gene cause a movement disorder, intellectual disability is not typically a feature. Note one report of two siblings with bi-allelic variants and much more severe phenotype including ID (PMID 33704598); however parents were asymptomatic so evidence for causality is limited. |
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| Intellectual disability syndromic and non-syndromic v0.3420 | OTUD5 |
Chirag Patel gene: OTUD5 was added gene: OTUD5 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: OTUD5 was set to X-LINKED: hemizygous mutation in males, biallelic mutations in females Publications for gene: OTUD5 were set to PMID: 33131077 Phenotypes for gene: OTUD5 were set to X-linked severe neurodevelopmental delay, hydrocephalus, and early lethality Review for gene: OTUD5 was set to RED Added comment: 13 male patients from a single family with three generations affected. Patients presented prenatally or during the neonatal period with IUGR, ventriculomegaly, hydrocephalus, hypotonia, congenital heart defects, hypospadias, and severe neurodevelopmental delay. The disease is typically fatal during infancy, mainly due to sepsis (pneumonias). Female carriers are asymptomatic. WGS in four individuals identified a unique candidate variant in the OTUD5 gene (NM_017602.3:c.598G > A, p.Glu200Lys). The variant cosegregated with the disease in 10 tested individuals. No functional studies. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3359 | ATIC | Zornitza Stark Marked gene: ATIC as ready | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3359 | ATIC | Zornitza Stark Gene: atic has been classified as Green List (High Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3359 | ATIC | Zornitza Stark Phenotypes for gene: ATIC were changed from to AICA-ribosiduria due to ATIC deficiency, MIM# 608688 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3358 | ATIC | Zornitza Stark Publications for gene: ATIC were set to | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3357 | ATIC | Zornitza Stark Mode of inheritance for gene: ATIC was changed from Unknown to BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3356 | ATIC | Zornitza Stark reviewed gene: ATIC: Rating: GREEN; Mode of pathogenicity: None; Publications: 15114530, 32557644; Phenotypes: AICA-ribosiduria due to ATIC deficiency, MIM# 608688; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3139 | FOXP4 |
Zornitza Stark changed review comment from: Eight unrelated individuals reported, seven de novo missense, and one individual with a truncating variant. Detailed phenotypic information available on 6. Overlapping features included speech and language delays, growth abnormalities, congenital diaphragmatic hernia (2/6), cervical spine abnormalities, and ptosis. Intellectual disability described as mild in 2, some had normal intellect despite the early challenges. Sources: Literature; to: Eight unrelated individuals reported, seven de novo missense, and one individual with a truncating variant. Detailed phenotypic information available on 6. Overlapping features included speech and language delays, growth abnormalities, congenital diaphragmatic hernia (2/6), cervical spine abnormalities, and ptosis. Intellectual disability described as mild in 2, some had normal intellect despite the early speech and language delays. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3139 | FOXP4 |
Zornitza Stark changed review comment from: Six unrelated individuals reported, 5 with missense variants in the forkhead box DNA-binding domain of FOXP4, and one individual with a truncating variant. Overlapping features included speech and language delays, growth abnormalities, congenital diaphragmatic hernia, cervical spine abnormalities, and ptosis. Sources: Literature; to: Eight unrelated individuals reported, seven de novo missense, and one individual with a truncating variant. Detailed phenotypic information available on 6. Overlapping features included speech and language delays, growth abnormalities, congenital diaphragmatic hernia (2/6), cervical spine abnormalities, and ptosis. Intellectual disability described as mild in 2, some had normal intellect despite the early challenges. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3139 | FOXP4 |
Zornitza Stark gene: FOXP4 was added gene: FOXP4 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: FOXP4 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: FOXP4 were set to 33110267 Phenotypes for gene: FOXP4 were set to Neurodevelopmental disorder; multiple congenital abnormalities Review for gene: FOXP4 was set to GREEN Added comment: Six unrelated individuals reported, 5 with missense variants in the forkhead box DNA-binding domain of FOXP4, and one individual with a truncating variant. Overlapping features included speech and language delays, growth abnormalities, congenital diaphragmatic hernia, cervical spine abnormalities, and ptosis. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3131 | STN1 |
Sue White gene: STN1 was added gene: STN1 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: STN1 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: STN1 were set to 32627942; 27432940 Phenotypes for gene: STN1 were set to cerebral calcification; premature ageing; bone marrow failure; retinal telangiactasia; hepatic fibrosis Penetrance for gene: STN1 were set to Complete Added comment: 3 unrelated patients reported with Coats-plus syndrome. Developmental delay noted in two. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3062 | SHMT2 |
Konstantinos Varvagiannis gene: SHMT2 was added gene: SHMT2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: SHMT2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: SHMT2 were set to 33015733 Phenotypes for gene: SHMT2 were set to Congenital microcephaly; Infantile axial hypotonia; Spastic paraparesis; Global developmental delay; Intellectual disability; Abnormality of the corpus callosum; Abnormal cortical gyration; Hypertrophic cardiomyopathy; Abnormality of the face; Proximal placement of thumb; 2-3 toe syndactyly Penetrance for gene: SHMT2 were set to Complete Review for gene: SHMT2 was set to GREEN Added comment: García‑Cazorla et al. (2020 - PMID: 33015733) report 5 individuals (from 4 families) with a novel brain and heart developmental syndrome caused by biallelic SHMT2 pathogenic variants. All affected subjects presented similar phenotype incl. microcephaly at birth (5/5 with OFC < -2 SD though in 2/5 cases N OFC was observed later), DD and ID (1/5 mild-moderate, 1/5 moderate, 3/5 severe), motor dysfunction in the form of spastic (5/5) paraparesis, ataxia/dysmetria (3/4), intention tremor (in 3/?) and/or peripheral neuropathy (2 sibs). They exhibited corpus callosum hypoplasia (5/5) and perisylvian microgyria-like pattern (4/5). Cardiac problems were reported in all, with hypertrophic cardiomyopathy in 4/5 (from 3 families) and atrial-SD in the 5th individual (1/5). Common dysmorphic features incl. long palpebral/fissures, eversion of lateral third of lower eylids, arched eyebrows, long eyelashes, thin upper lip, short Vth finger, fetal pads, mild 2-3 toe syndactyly, proximally placed thumbs. Biallelic variants were identified following exome sequencing in all (other investigations not mentioned). Identified variants were in all cases missense SNVs or in-frame del, which together with evidence from population databases and mouse model might suggest a hypomorphic effect of variants and intolerance/embryonic lethality for homozygous LoF ones. SHMT2 encodes the mitohondrial form of serine hydroxymethyltransferase. The enzyme transfers one-carbon units from serine to tetrahydrofolate (THF) and generates glycine and 5,10,methylene-THF. Mitochondrial defect was suggested by presence of ragged red fibers in myocardial biopsy of one patient. Quadriceps and myocardial biopsies of the same individual were overall suggestive of myopathic changes. While plasma metabolites were within N range and SHMT2 protein levels not significantly altered in patient fibroblasts, the authors provide evidence for impaired enzymatic function eg. presence of the SHMT2 substrate (THF) in patient but not control (mitochondria-enriched) fibroblasts , decrease in glycine/serine ratios, impared folate metabolism. Patient fibroblasts displayed impaired oxidative capacity (reduced ATP levels in a medium without glucose, diminished oxygen consumption rates). Mitochondrial membrane potential and ROS levels were also suggestive of redox malfunction. Shmt2 ko in mice was previously shown to be embryonically lethal attributed to severe mitochondrial respiration defects, although there was no observed brain metabolic defect. The authors performed Shmt2 knockdown in motoneurons in Drosophila, demonstrating neuromuscular junction (# of satellite boutons) and motility defects (climbing distance/velocity). Overall this gene can be considered for inclusion with (probably) green rating in gene panels for ID, metabolic / mitochondrial disorders, cardiomyopathy, congenital microcephaly, corpus callosum anomalies, etc. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.3030 | CNOT1 | Zornitza Stark Phenotypes for gene: CNOT1 were changed from Holoprosencephaly 12, with or without pancreatic agenesis 618500 to Vissers-Bodmer syndrome, MIM#619033; Holoprosencephaly 12, with or without pancreatic agenesis 618500 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2835 | MADD | Konstantinos Varvagiannis reviewed gene: MADD: Rating: GREEN; Mode of pathogenicity: None; Publications: 28940097, 29302074, 32761064; Phenotypes: Global developmental delay / Intellectual disability / Seizures, Global developmental delay / Intellectual disability / Seizures / Abnormality of the endocrine system / Exocrine pancreatic insufficiency / Constipation / Diarrhea / Anemia / Thrombocytopenia / Abnormality of the autonomic nervous system; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2790 | LARS |
Konstantinos Varvagiannis gene: LARS was added gene: LARS was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: LARS was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: LARS were set to 32699352 Phenotypes for gene: LARS were set to Infantile liver failure syndrome 1, MIM# 615438 Penetrance for gene: LARS were set to Complete Review for gene: LARS was set to GREEN Added comment: Please consider inclusion with amber/green rating in the current panel. Biallelic pathogenic LARS1 variants cause Infantile liver failure syndrome 1, MIM# 615438. Lenz et al (2020 - PMID: 32699352) review the phenotype of 25 affected individuals from 15 families. Seizures occurred in 19/24 and were commonly associated with infections. Encephalopathic episodes (in 13 patients) accompanied by seizures up to status epilepticus occurred independently of hepatic decompensation. In addition 22/24 presented with neurodevelopmental delay. The authors comment that cognitive impairment was present in 13/17 individuals (mild-severe) whereas most presented with learning disabilities. These patients will most likely investigated for their liver disease (although presentation was highly variable and/or very mild in few). The gene encodes a cytoplasmic amino-acyl tRNA synthetase (ARS) with neurologic manifestations observed in almost all patients (and seizures / DD and ID common to other disorders due to mutations in other genes encoding for ARSs). Please note that the HGNC approved symbol for this gene is LARS1. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.2627 | UGDH |
Konstantinos Varvagiannis gene: UGDH was added gene: UGDH was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: UGDH was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: UGDH were set to 32001716 Phenotypes for gene: UGDH were set to Epileptic encephalopathy, early infantile, 84 - MIM #618792 Penetrance for gene: UGDH were set to Complete Review for gene: UGDH was set to GREEN Added comment: Hengel et al (2020 - PMID: 32001716) report on 36 individuals with biallelic UGDH pathogenic variants. The phenotype corresponded overall to a developmental epileptic encephalopathy with hypotonia, feeding difficulties, severe global DD, moderate or commonly severe ID in all. Hypotonia and motor disorder (incl. spasticity, dystonia, ataxia, chorea, etc) often occurred prior to the onset of seizures. A single individual did not present seizures and 2 sibs had only seizures in the setting of fever. Affected subjects were tested by exome sequencing and UGDH variants were the only/best candidates for the phenotype following also segregation studies. Many were compound heterozygous or homozygous (~6 families were consanguineous) for missense variants and few were compound heterozygous for missense and pLoF variants. There were no individuals with biallelic pLoF variants identified. Parental/sib studies were all compatible with AR inheritance mode. UGDH encodes the enzyme UDP-glucose dehydrogenase which converts UDP-glucose to UDP-glucuronate, the latter being a critical component of the glycosaminoglycans, hyaluronan, chondroitin sulfate, and heparan sulfate [OMIM]. Patient fibroblast and biochemical assays suggested a LoF effect of variants leading to impairment of UGDH stability, oligomerization or enzymatic activity (decreased UGDH-catalyzed reduction of NAD+ to NADH / hyaluronic acid production which requires UDP-glucuronate). Attempts to model the disorder using an already developped zebrafish model (for a hypomorphic LoF allele) were unsuccessful as fish did not exhibit seizures spontaneously or upon induction with PTZ. Modelling of the disorder in vitro using patient-derived cerebral organoids demonstrated smaller organoids due to reduced number of proliferating neural progenitors. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.2261 | STRADA |
Zornitza Stark gene: STRADA was added gene: STRADA was added to Intellectual disability syndromic and non-syndromic. Sources: Expert list Mode of inheritance for gene: STRADA was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: STRADA were set to 17522105; 27170158; 28688840 Phenotypes for gene: STRADA were set to Polyhydramnios, megalencephaly, and symptomatic epilepsy, MIM# 611087 Review for gene: STRADA was set to GREEN Added comment: Seven distantly related Menonite children plus four other unrelated families reported. Sources: Expert list |
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| Intellectual disability syndromic and non-syndromic v0.2175 | PTRH2 |
Zornitza Stark gene: PTRH2 was added gene: PTRH2 was added to Intellectual disability syndromic and non-syndromic. Sources: Expert list Mode of inheritance for gene: PTRH2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PTRH2 were set to 25574476; 28175314; 28328138; 25558065; 27129381 Phenotypes for gene: PTRH2 were set to Infantile-onset multisystem neurologic, endocrine, and pancreatic disease, MIM# 616263 Review for gene: PTRH2 was set to AMBER Added comment: A spectrum of features associated with bi-allelic variants in this gene; however, ID only reported as a feature in two families. Sources: Expert list |
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| Intellectual disability syndromic and non-syndromic v0.2001 | GNAQ | Zornitza Stark Tag somatic tag was added to gene: GNAQ. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1823 | EBP | Zornitza Stark Added comment: Comment when marking as ready: CDP lethal in males (unless mosaic) and females generally have normal intellectual development. Hypomorphic variants in males result in MEND, which has ID as a feature (carrier females for these variants generally asymptomatic). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1821 | EBP | Zornitza Stark Tag somatic tag was added to gene: EBP. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1795 | GNAS | Michelle Torres reviewed gene: GNAS: Rating: GREEN; Mode of pathogenicity: None; Publications: PMID: 29072892; Phenotypes: 1. ACTH-independent macronodular adrenal hyperplasia (219080) Somatic Mutations, 2. McCune-Albright syndrome, somatic, mosaic (174800), 3. Osseous heteroplasia, progressive (166350) AD, 4. Pituitary adenoma 3, multiple types, somatic (617686), 5. Pseudohypoparathyroidism Ia (103580) AD, 6. Pseudohypoparathyroidism Ib (603233) AD, 7. Pseudohypoparathyroidism Ic (612462) AD, 8. Pseudopseudohypoparathyroidism (612463) AD; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, imprinted status unknown | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1795 | GNAS | Michelle Torres reviewed gene: GNAS: Rating: GREEN; Mode of pathogenicity: None; Publications: PMID: 29072892; Phenotypes: 1. ACTH-independent macronodular adrenal hyperplasia (219080) Somatic Mutations, 2. McCune-Albright syndrome, somatic, mosaic (174800), 3. Osseous heteroplasia, progressive (166350) AD, 4. Pituitary adenoma 3, multiple types, somatic (617686), 5. Pseudohypoparathyroidism Ia (103580) AD, 6. Pseudohypoparathyroidism Ib (603233) AD, 7. Pseudohypoparathyroidism Ic (612462) AD, 8. Pseudopseudohypoparathyroidism (612463) AD; Mode of inheritance: None | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1727 | CTBP1 |
Sebastian Lunke gene: CTBP1 was added gene: CTBP1 was added to Intellectual disability syndromic and non-syndromic. Sources: Expert list Mode of inheritance for gene: CTBP1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: CTBP1 were set to 27094857; 28955726; 31041561 Phenotypes for gene: CTBP1 were set to Hypotonia, ataxia, developmental delay, and tooth enamel defect syndrome, 617915 gene: CTBP1 was marked as current diagnostic Added comment: From GEL: There are 12 individuals reported from 3 papers (2 papers from the same group). All 12 individuals have the same heterozygous missense variant (R331W in NM_001012614.1; R342W in NM_001328.2). It is a de novo variant in all cases except one where it's inherited from a somatic parent. The phenotype of all 12 is summarised in Table 1 of PMID:31041561. Global DD is a consistent feature (varying severity). ID is recorded in several patients. Developmental motor regression recorded in 4 patients (2 of which also had cognitive regression). Authors note that healthy individuals with heterozygous LOF alleles have been reported. Sources: Expert list |
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| Intellectual disability syndromic and non-syndromic v0.1727 | CTBP1 |
Sebastian Lunke gene: CTBP1 was added gene: CTBP1 was added to Intellectual disability syndromic and non-syndromic. Sources: Expert list Mode of inheritance for gene: CTBP1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: CTBP1 were set to 27094857; 28955726; 31041561 Phenotypes for gene: CTBP1 were set to Hypotonia, ataxia, developmental delay, and tooth enamel defect syndrome, 617915 gene: CTBP1 was marked as current diagnostic Added comment: From GEL: There are 12 individuals reported from 3 papers (2 papers from the same group). All 12 individuals have the same heterozygous missense variant (R331W in NM_001012614.1; R342W in NM_001328.2). It is a de novo variant in all cases except one where it's inherited from a somatic parent. The phenotype of all 12 is summarised in Table 1 of PMID:31041561. Global DD is a consistent feature (varying severity). ID is recorded in several patients. Developmental motor regression recorded in 4 patients (2 of which also had cognitive regression). Authors note that healthy individuals with heterozygous LOF alleles have been reported. Sources: Expert list |
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| Intellectual disability syndromic and non-syndromic v0.1718 | CNOT1 |
Sebastian Lunke gene: CNOT1 was added gene: CNOT1 was added to Intellectual disability syndromic and non-syndromic. Sources: Expert list Mode of inheritance for gene: CNOT1 was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: CNOT1 were set to 31006510; 21679367; 31006513 Phenotypes for gene: CNOT1 were set to Holoprosencephaly 12, with or without pancreatic agenesis 618500 Review for gene: CNOT1 was set to GREEN gene: CNOT1 was marked as current diagnostic Added comment: From GEL: More than three independent families previously described Sources: Expert list |
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| Intellectual disability syndromic and non-syndromic v0.1283 | TARS |
Chirag Patel gene: TARS was added gene: TARS was added to Intellectual disability, syndromic and non-syndromic_GHQ_VCGS. Sources: Literature Mode of inheritance for gene: TARS was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: TARS were set to PMID: 31374204 Phenotypes for gene: TARS were set to Trichothiodystrophy 7, nonphotosensitive; OMIM #618546 Review for gene: TARS was set to AMBER Added comment: Clinical features of trichothiodystrophy (TTD) include ichthyosis, intellectual disability, decreased fertility, short stature. 2 unrelated patients with non-photosensitive-TTD, in whom limited clinical information was available (one with DD): one compound heterozygous TARS variants, second homozygous for TARS variant. They showed that the variants had a profound effect on TARS protein stability and enzymatic function. Sources: Literature |
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| Intellectual disability syndromic and non-syndromic v0.1031 | PSAP | Zornitza Stark Phenotypes for gene: PSAP were changed from to Metachromatic leukodystrophy due to SAP-b deficiency, MIM#249900 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.1029 | PSAP | Zornitza Stark reviewed gene: PSAP: Rating: GREEN; Mode of pathogenicity: None; Publications: ; Phenotypes: Metachromatic leukodystrophy due to SAP-b deficiency, MIM#249900; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.293 | GNAQ | Zornitza Stark Phenotypes for gene: GNAQ were changed from to Sturge-Weber syndrome, somatic, mosaic, MIM#185300 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.291 | GNAQ | Zornitza Stark reviewed gene: GNAQ: Rating: AMBER; Mode of pathogenicity: None; Publications: ; Phenotypes: Sturge-Weber syndrome, somatic, mosaic, MIM#185300; Mode of inheritance: Other | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.263 | GATA6 | Zornitza Stark Phenotypes for gene: GATA6 were changed from to Pancreatic agenesis and congenital heart defects, MIM#600001 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.260 | GATA6 | Zornitza Stark reviewed gene: GATA6: Rating: GREEN; Mode of pathogenicity: None; Publications: 22158542; Phenotypes: Pancreatic agenesis and congenital heart defects, MIM#600001; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.44 | COX4I2 | Zornitza Stark Phenotypes for gene: COX4I2 were changed from to Exocrine pancreatic insufficiency, dyserythropoietic anemia, and calvarial hyperostosis, MIM#612714 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.41 | COX4I2 | Zornitza Stark reviewed gene: COX4I2: Rating: RED; Mode of pathogenicity: None; Publications: 19268275, 22730437; Phenotypes: Exocrine pancreatic insufficiency, dyserythropoietic anemia, and calvarial hyperostosis, MIM#612714; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.0 | ATIC |
Zornitza Stark gene: ATIC was added gene: ATIC was added to Intellectual disability, syndromic and non-syndromic_GHQ. Sources: Expert Review Green,Genetic Health Queensland Mode of inheritance for gene: ATIC was set to Unknown |
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