Possible association between childhood absence epilepsy and the gene encoding GABRB3

Background: Childhood Absence Epilepsy (CAE) is considered to have a predom inantly, perhaps exclusively, generic background. To date, genes responsibl e far susceptibility to CAE have not been identified. The object of the pre sent study was to test association between CAE and the genes encoding the g amma-aminobutyric acid (GABA) type-A receptor subunits alpha 5 (GABRA5) and beta 3 (GABRB3) located on the long arm of chromosome 15 (15q11-q13), Methods: A family-based candidate gene approach was applied: 50 Austrian nu clear families ascertained for the presence of an affected child were inves tigated. GABRA5 and GABRB3 subunit genes were genotyped using DNA gained fr om peripheral blood samples by Polymerase Chain Reactions (PCR). Generic as sociation was tested using a Monte Carlo Version of the multi-allele Transm ission-Disequilibrium Test (TDT). Results: The TDT displayed significant overall association with GABRB3 (p = .0118). Conclusions: The present data suggest that the tested polymorphism may be e ither directly involved in the etiology of CAE or in linkage disequilibrium with disease-predisposing sites. Biol Psychiatry 1999;46:997-1002 (C) 1999 Society of Biological Psychiatry.