GABA_B receptor 1 polymorphism (G1465A) and temporal lobe epilepsy

Purpose: To reevaluate the genetic contribution of the polymorphism G1465A of the gene coding for gamma-aminobutyric acid (GABA)B receptor 1 subunit [GABAB(1)] in a sample of French patients with temporal lobe epilepsy (TLE) and to perform an exploratory analysis in other phenotypic subgroups. Methods: The 134 patients were genotyped for the polymorphism G1465A. This sample was divided in two groups. The first one had patients with nonlesional TLE, and the second one, with lesional TLE. Then these two groups were compared with a sample of 145 healthy individuals. Results: The genotype and allele distributions for the polymorphism G1465A showed no difference between patients and controls. Conclusions: The association between the variant G1465A and the sample of patients could not be replicated, so these results exclude a major effect of this polymorphism in the susceptibility to nonlesional TLE. Larger samples should be tested to determine whether the G1465A in exon 7 of the GABAB(1) receptor gene is a susceptibility factor for nonlesional TLE.