Browsing by Author "Raymond, FL"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- De Novo Truncating Mutations in WASF1 Cause Intellectual Disability with SeizuresPublication . Ito, Y; Carss, KJ; Duarte, ST; Hartley, T; Keren, B; Kurian, MA; Marey, I; Charles, P; Mendonça, C; Nava, C; Pfundt, R; Sanchis-Juan, A; van Bokhoven, H; van Essen, A; van Ravenswaaij-Arts, C; Boycott, KM; Kernohan, KD; Dyack, S; Raymond, FLNext-generation sequencing has been invaluable in the elucidation of the genetic etiology of many subtypes of intellectual disability in recent years. Here, using exome sequencing and whole-genome sequencing, we identified three de novo truncating mutations in WAS protein family member 1 (WASF1) in five unrelated individuals with moderate to profound intellectual disability with autistic features and seizures. WASF1, also known as WAVE1, is part of the WAVE complex and acts as a mediator between Rac-GTPase and actin to induce actin polymerization. The three mutations connected by Matchmaker Exchange were c.1516C>T (p.Arg506Ter), which occurs in three unrelated individuals, c.1558C>T (p.Gln520Ter), and c.1482delinsGCCAGG (p.Ile494MetfsTer23). All three variants are predicted to partially or fully disrupt the C-terminal actin-binding WCA domain. Functional studies using fibroblast cells from two affected individuals with the c.1516C>T mutation showed a truncated WASF1 and a defect in actin remodeling. This study provides evidence that de novo heterozygous mutations in WASF1 cause a rare form of intellectual disability.
- Structural Analysis of Pathogenic Missense Mutations in GABRA2 and Identification of a Novel de Novo Variant in the Desensitization GatePublication . Sanchis-Juan, A; Hasenahuer, MA; Baker, JA; McTague, A; Barwick, K; Kurian, MA; Duarte, ST; Carss, KJ; Thornton, J; Raymond, FLBackground: Cys-loop receptors control neuronal excitability in the brain and their dysfunction results in numerous neurological disorders. Recently, six missense variants in GABRA2, a member of this family, have been associated with early infantile epileptic encephalopathy (EIEE). We identified a novel de novo missense variant in GABRA2 in a patient with EIEE and performed protein structural analysis of the seven variants. Methods: The novel variant was identified by trio whole-genome sequencing. We performed protein structural analysis of the seven variants, and compared them to previously reported pathogenic mutations at equivalent positions in other Cys-loop receptors. Additionally, we studied the distribution of disease-associated variants in the transmembrane helices of these proteins. Results: The seven variants are in the transmembrane domain, either close to the desensitization gate, the activation gate, or in inter-subunit interfaces. Six of them have pathogenic mutations at equivalent positions in other Cys-loop receptors, emphasizing the importance of these residues. Also, pathogenic mutations are more common in the pore-lining helix, consistent with this region being highly constrained for variation in control populations. Conclusion: Our study reports a novel pathogenic variant in GABRA2, characterizes the regions where pathogenic mutations are in the transmembrane helices, and underscores the value of considering sequence, evolutionary, and structural information as a strategy for variant interpretation of novel missense mutations.