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| Intellectual disability syndromic and non-syndromic v0.5653 | RAP1B | Zornitza Stark Phenotypes for gene: RAP1B were changed from Syndromic disease, MONDO:0002254, RAP1B-related to Thrombocytopenia 1 with multiple congenital anomalies and dysmorphic facies, MIM# 620654 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5652 | RAP1B | Zornitza Stark edited their review of gene: RAP1B: Changed phenotypes: Thrombocytopenia 1 with multiple congenital anomalies and dysmorphic facies, MIM# 620654 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5373 | RAP1B | Zornitza Stark Phenotypes for gene: RAP1B were changed from RAP1B‐associated phenotype, no OMIM # to Syndromic disease, MONDO:0002254, RAP1B-related | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5372 | RAP1B | Zornitza Stark edited their review of gene: RAP1B: Changed phenotypes: Syndromic disease, MONDO:0002254, RAP1B-related | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.4053 | PLXNA2 |
Konstantinos Varvagiannis gene: PLXNA2 was added gene: PLXNA2 was added to Intellectual disability syndromic and non-syndromic. Sources: Literature,Other Mode of inheritance for gene: PLXNA2 was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: PLXNA2 were set to 34327814 Phenotypes for gene: PLXNA2 were set to Intellectual disability; Abnormality of the face; Failure to thrive; Abnormal heart morphology Penetrance for gene: PLXNA2 were set to Incomplete Review for gene: PLXNA2 was set to AMBER Added comment: Altuame et al (2021 - PMID: 34327814) describe 3 individuals from 2 consanguineous Arab families with biallelic PLXNA2 variants. The index patient from the 1st family presented with CHD (hypoplastic right ventricle, ASD), DD and moderate ID (IQ of 40), failure to thrive as well as some dysmorphic features (obtuse mandibular angle, mild overbite, synophrys with downslanting p-f, strabismus, etc). There were additional features (eg. postaxial polydactyly) which were found in other affected and unaffected family members. Exome sequencing with autozygome analysis revealed homozygosity for a PLXNA2 stopgain variant (NM_025179:c.3603C>A / p.(Cys1201*)). Sanger confirmation was carried out and segregation analyses confirmed carrier status of the unaffected parents and a sib as well as a brother homozygous for the same variant. Clinical evaluation of the latter, following this finding revealed borderline intellectual functioning, ADHD, failure to thrive. There was no mandibular anomaly or overbite and no clinical evidence of CHD (no echo performed). The index patient from the 2nd consanguineous family was evaluated for ID (IQ of 63), with previous borderline motor development, ADHD and some dysmorphic features (obtuse mandibular angle and overbite). There was no clinical evidence of CHD (no echo performed). Exome sequencing with autozygosity mapping revealed a homozygous missense PLXNA2 variant (c.3073G>A / p.(Asp1025Asn), present only once in gnomAD (htz), with rather non-concordant in silico predictions SIFT 0.22, PolyPhen 0.682 and CADD 23.5. The aa was however highly conserved. Segregation analysis confirmed carrier state of the parents and 2 unaffected sibs, with a 3rd sib homozygous for the wt allele. As the authors discuss: *PLXNA2 belongs to the plexin family of genes, encoding transmbembrane proteins functioning as semaphorin receptors. It has predominant expression in neural tissue. The protein is thought to bind semaphorin-3A, -3C or -5 followed by plexin A2 dimerization, activation of its GTPase-activating protein domain, negative regulation of Rap1B GTPase and initiation of a signal transduction cascade mediating axonal repulsion/guidance, dendritic guidance, neuronal migration. *Murine Plxna2 knockout models display structural brain defects. In addition they display congenital heart defects incl. persistent truncus arteriosus and interrupted aortic arch. *Rare CNVs in adult humans with tetralogy of Fallot have suggested a potential role of PLXNA2 in cardiac development and CHD. *Expression and the role of PLXNA2 in human chondrocytes as well as a GWAS in 240 japanese patients with mandibular prognathism where PLXNA2 was suggested as a susceptibility locus. Overall, the authors recognize some common features (as for cognitive functioning, some dysmorphic features incl. obtuse mandibular angle and overbite in 2 unrelated subjects, failure to thrive 3/3) and provide plausible explanations for the variability / discordance of others eg: - Cyanotic heart disease explaining discordance in cognitive outcome among sibs - Incomplete penetrance for CHD (and/or ID or mandibular anomaly) as for few AR disorders and/or - Additional pathogenic variants possibly explaining the CHD in the first subject. There is no associated phenotype in OMIM or G2P. SysID includes PLXNA2 among the candidate ID genes. Sources: Literature, Other |
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| Intellectual disability syndromic and non-syndromic v0.3267 | RAP1B | Zornitza Stark Publications for gene: RAP1B were set to PMID: 32627184 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3266 | RAP1B | Zornitza Stark Classified gene: RAP1B as Green List (high evidence) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3266 | RAP1B | Zornitza Stark Gene: rap1b has been classified as Green List (High Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3265 | RAP1B | Zornitza Stark edited their review of gene: RAP1B: Added comment: Another individual with de novo missense variant from a Kabuki-like cohort but note facial gestalt was not typical, had DD.; Changed rating: GREEN; Changed publications: 32627184, 26280580 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3265 | RAP1B | Zornitza Stark reviewed gene: RAP1B: Rating: AMBER; Mode of pathogenicity: None; Publications: 32627184; Phenotypes: ; Mode of inheritance: MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3265 | RAP1B | Zornitza Stark Marked gene: RAP1B as ready | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3265 | RAP1B | Zornitza Stark Gene: rap1b has been classified as Amber List (Moderate Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3265 | RAP1B | Zornitza Stark Classified gene: RAP1B as Amber List (moderate evidence) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3265 | RAP1B | Zornitza Stark Gene: rap1b has been classified as Amber List (Moderate Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3264 | RAP1B |
Chirag Patel gene: RAP1B was added gene: RAP1B was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: RAP1B was set to MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted Publications for gene: RAP1B were set to PMID: 32627184 Phenotypes for gene: RAP1B were set to RAP1B‐associated phenotype, no OMIM # Review for gene: RAP1B was set to RED Added comment: De novo variants in the RAP1B gene (c.35G>T p.(Gly12Val) and c.178G>C p.(Gly60Arg)) in two unrelated patients with thrombocytopenia, microcephaly, learning difficulties, renal malformations, structural anomalies of the brain and other features (not Kabuki like). RAP1B is a member of the RAS superfamily of small GTPases. There is strong evidence that the p.Gly12Val and p.Gly60Arg variants in the RAP1B gene lead into a dysregulation of the downstream pathway. Both substitutions have been described previously as dominant constitutively active in RAS‐related proteins (gain of function variants). Sources: Literature |
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