Mutation screen of the GABA(A) receptor gamma 2 subunit gene in Chinese patients with childhood absence epilepsy.

Childhood absence epilepsy (CAE) is considered to be a genetic disease, the genes responsible for which have not yet been identified. To investigate whether or not GABA(A) receptor gamma 2 subunit gene (GABRG2) is the susceptibility gene for CAE in the Chinese population, we screened 68 CAE patients of Han ethnicity from North China for mutations in the nine exons of GABRG2. Although we found no mutation in the exons of GABRG2, we did identify two single nucleotide polymorphisms (SNPs) in exon 3 and exon 5. Using the two SNPs as markers, we carried out a transmission/disequilibrium test (TDT) in 68 trios with CAE. TDT results showed that there were no significant discrepancies between the CAE patients and 'internal controls' in allele frequencies of the two SNPs. We postulate that the GABRG2 gene might be neither a susceptibility gene for CAE nor in linkage disequilibrium with disease-predisposing sites in the Chinese population. Copyright 2002 Elsevier Science Ireland Ltd.