Objective: To investigate whether or not the gamma-aminobutyric acid (GABA) receptor subtype A genes GABRA5 and GABRB3 are associated with childhood absence epilepsy (CAE).
Methods: Two microsatellite DNA, GABRA5 and GABRB3, adjoining to chromosome 15q11.2-q12 were used as genetic markers. Both case-control study and transmission/disequilibrium test (TDT) as well as fluorescence-based semi-automated genotyping technique were used in 90 trios with CAE and 100 controls to conduct association analysis.
Results: The allele frequencies of the 2 microsatellite DNA in Chinese normal population are in good agreement with Hardy-Weinberg equilibrium. The polymorphism information content of microsatellite DNA GABRA5 and GABRB3, are 0.80 and 0.66 respectively. The allele 2 frequency of microsatellite DNA GABRA5 and the allele 5 frequency of microsatellite DNA GABRB3 are significantly higher in CAE patients than those in normal controls(P<0.001).
Conclusion: Both microsatellite DNA GABRA5 and GABRB3 are good genetic markers. The gamma-aminobutyric acid receptor subtype A genes GABRA5 and GABRB3 may be directly involved either in the etiology of CAE or in linkage disequilibrium with disease-predisposing sites.