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| Intellectual disability syndromic and non-syndromic v0.5029 | TBC1D2B | Chirag Patel Classified gene: TBC1D2B as Green List (high evidence) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5029 | TBC1D2B | Chirag Patel Gene: tbc1d2b has been classified as Green List (High Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.5028 | TBC1D2B | Chirag Patel reviewed gene: TBC1D2B: Rating: GREEN; Mode of pathogenicity: None; Publications: PMID: 36029130; Phenotypes: Neurodevelopmental disorder with seizures and gingival overgrowth, OMIM #619323; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3782 | TBC1D2B | Zornitza Stark Phenotypes for gene: TBC1D2B were changed from Global developmental delay; Intellectual disability; Seizures; Gingival overgrowth; Behavioral abnormality; Abnormality of the mandible; Abnormality of brain morphology; Abnormality of the eye; Hearing abnormality to Neurodevelopmental disorder with seizures and gingival overgrowth (NEDSGO), MIM#619323; Global developmental delay; Intellectual disability; Seizures; Gingival overgrowth; Behavioral abnormality; Abnormality of the mandible; Abnormality of brain morphology; Abnormality of the eye; Hearing abnormality | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.3781 | TBC1D2B | Zornitza Stark reviewed gene: TBC1D2B: Rating: AMBER; Mode of pathogenicity: None; Publications: ; Phenotypes: Neurodevelopmental disorder with seizures and gingival overgrowth (NEDSGO), MIM#619323; Mode of inheritance: BIALLELIC, autosomal or pseudoautosomal | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2758 | TBC1D2B | Zornitza Stark Marked gene: TBC1D2B as ready | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2758 | TBC1D2B | Zornitza Stark Gene: tbc1d2b has been classified as Amber List (Moderate Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2758 | TBC1D2B | Zornitza Stark Classified gene: TBC1D2B as Amber List (moderate evidence) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2758 | TBC1D2B | Zornitza Stark Gene: tbc1d2b has been classified as Amber List (Moderate Evidence). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Intellectual disability syndromic and non-syndromic v0.2750 | TBC1D2B |
Konstantinos Varvagiannis gene: TBC1D2B was added gene: TBC1D2B was added to Intellectual disability syndromic and non-syndromic. Sources: Literature Mode of inheritance for gene: TBC1D2B was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: TBC1D2B were set to 32623794 Phenotypes for gene: TBC1D2B were set to Global developmental delay; Intellectual disability; Seizures; Gingival overgrowth; Behavioral abnormality; Abnormality of the mandible; Abnormality of brain morphology; Abnormality of the eye; Hearing abnormality Penetrance for gene: TBC1D2B were set to Complete Review for gene: TBC1D2B was set to AMBER Added comment: Harms et al (2020 - PMID: 32623794) report on 3 unrelated individuals with biallelic pLoF TBC1D2B variants. Features included cognitive impairment (mild ID in one case, regression at the age of 12y in another, hypotonia and delayed milestones in a third aged 8m), seizures (3/3 - variable age of onset) and/or gingival overgrowth (2/3 - prior to initiation of AEDs). Other findings included behavioral abnormalities, mandibular anomalies, abnormal brain imaging and ophthalmologic or (rarely) audiometric evaluations. All were born to non-consanguineous couples and additional investigations were performed in some. Variants were identified by WES or trio WGS, with Sanger confirmation/compatible segregation analyses. In line with the pLoF variants, mRNA studies in fibroblasts from 2 unrelated affected individuals demonstrated significantly reduced (~80-90%) TBC1C2D mRNA levels compared to controls, restored following cycloheximide treatment. Protein was absent in patient fibroblasts. TBC-domain containing GTPase activating proteins are known as key regulators of RAB GTPase activity. TBC1D2B was shown to colocalize with RAB5-positive endocytic vesicles. CRISPR/Cas9-mediated ko of TBC1D2B in HeLa cells suggested a role in EGF receptor endocytosis and decreased cell viability of TBC1D2B-deficient HeLa cells upon serum deprivation. Genes encoding other TBC domain-containg GTPase-activating proteins, e.g. TBC1D7 and TBC1D20, TBC1D24 are associated with recessive neurodevelopmental disorders (with ID and/or seizures) and the pathophysiological defect in TBC1D2B-related disorder (deficit in vesicle trafficking and/or cell survival) is proposed to be similar to that of TBC1D24. Overall this gene can be considered for inclusion with amber/green rating in the ID panel and green in epilepsy panel. Sources: Literature |
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