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ABSTRACT: Objective
γ-Aminobutyric acid (GABA)A -receptor subunit variants have recently been associated with neurodevelopmental disorders and/or epilepsy. The phenotype linked with each gene is becoming better known. Because of the common molecular structure and physiological role of these phenotypes, it seemed interesting to describe a putative phenotype associated with GABAA -receptor-related disorders as a whole and seek possible genotype-phenotype correlations.Methods
We collected clinical, electrophysiological, therapeutic, and molecular data from patients with GABAA -receptor subunit variants (GABRA1, GABRB2, GABRB3, and GABRG2) through a national French collaboration using the EPIGENE network and compared these data to the one already described in the literature.Results
We gathered the reported patients in three epileptic phenotypes: 15 patients with fever-related epilepsy (40%), 11 with early developmental epileptic encephalopathy (30%), 10 with generalized epilepsy spectrum (27%), and 1 patient without seizures (3%). We did not find a specific phenotype for any gene, but we showed that the location of variants on the transmembrane (TM) segment was associated with a more severe phenotype, irrespective of the GABAA -receptor subunit gene, whereas N-terminal variants seemed to be related to milder phenotypes.Significance
GABAA -receptor subunit variants are associated with highly variable phenotypes despite their molecular and physiological proximity. None of the genes described here was associated with a specific phenotype. On the other hand, it appears that the location of the variant on the protein may be a marker of severity. Variant location may have important weight in the development of targeted therapeutics.
SUBMITTER: Maillard PY
PROVIDER: S-EPMC9804453 | biostudies-literature | 2022 Oct
REPOSITORIES: biostudies-literature
Maillard Pierre-Yves PY Baer Sarah S Schaefer Élise É Desnous Béatrice B Villeneuve Nathalie N Lépine Anne A Fabre Alexandre A Lacoste Caroline C El Chehadeh Salima S Piton Amélie A Porter Louise Frances LF Perriard Caroline C Wardé Marie-Thérèse Abi MA Spitz Marie-Aude MA Laugel Vincent V Lesca Gaëtan G Putoux Audrey A Ville Dorothée D Mignot Cyril C Héron Delphine D Nabbout Rima R Barcia Giulia G Rio Marlène M Roubertie Agathe A Meyer Pierre P Paquis-Flucklinger Véronique V Patat Olivier O Lefranc Jérémie J Gerard Marion M de Bellescize Julietta J Villard Laurent L De Saint Martin Anne A Milh Mathieu M
Epilepsia 20220813 10
<h4>Objective</h4>γ-Aminobutyric acid (GABA)<sub>A</sub> -receptor subunit variants have recently been associated with neurodevelopmental disorders and/or epilepsy. The phenotype linked with each gene is becoming better known. Because of the common molecular structure and physiological role of these phenotypes, it seemed interesting to describe a putative phenotype associated with GABA<sub>A</sub> -receptor-related disorders as a whole and seek possible genotype-phenotype correlations.<h4>Method ...[more]