Single Nucleotide Polymorphisms of GABRG2 in Idiopathic Generalized Epilepsies(IGEs)

Yeon, Yeong Heum; Seung, So Jin; Hwang, Hui Sung; Kim, Eugene; Kim, Young Hoon; Lee, In Goo; Chung, Seung Yun

Abstract

PURPOSE: Mutations in gamma-aminobutyric acid(GABA) A receptor gamma2 subunit gene (GABRG2) were independently identified in families of generalized epilepsy with febrile seizures plus(GEFS+) and families of absence epilepsy and febrile seizures(FSs). The present study assessed the role of GABRG2 gene in idiopathic generalized epilepsies(IGEs) of Korean population.
METHODS
Twenty-three IGEs and 94 healthy control subjects were selected through a collaborative study of Catholic Child Neurology Research Group. The SNP211037 of GABRG2 were screened by DHPLC. DNA fragments showing variant chromatograms were subsequently sequenced. Genotypes and allelic frequencies for GABRG2 gene polymorphism in three groups were compared.
RESULTS
Genotypes and allelic frequencies of the gamma2 subunit of the GABA receptor gene(SNP211037) in both groups were not significantly different. The most common genotypes for GABRG2(SNP211037) gene in both groups were T/C heterozygote. The allele C and T frequencies for GABRG2(SNP211037) in the IGEs group were 45.7% and 54.3%, respectively and in healthy control group, 42.6% and 57.4%, respectively. The number of individuals with the GABRG2 (SNP211037)-C/C genotype in the IGEs group was greater compared with that in the healthy control group(21.7% versus 12.8%). The odds ratio for developing IGEs in individuals with the GABRG2 (SNP211037)-CC genotype was 1.65 compared with individuals with the GABRG2 (SNP211037)-T/T genotype, which was not significantly different.
CONCLUSION
These data suggest that genomic variations of GABRG2 might not be one of the susceptibility factors for IGEs in the Korean population.