Positive association of the human GABA-A-receptor beta 2 subunit gene haplotype with schizophrenia in the Chinese Han population.

A converging body of evidence implicates the gamma-amino butyric acid neurotransmitter system in the pathogenesis of schizophrenia. Recently, Lo et al. reported strong positive association between schizophrenia and GABRB2, demonstrated by single markers and haplotypes of five markers in introns of GABRB2, rs6556547, rs1816071, rs194072, rs252944, and rs187269. To validate this linkage disequilibrium report, we genotyped these five SNPs and additional rs1816072 in 352 Chinese Han family trios. Though we failed to detect any positive results in single markers, we did find a significant haplotypic association (global p = 0.00157-0.00588) which had not been identified in Lo's study. Our data indicated that the haplotype 'GACTCT' (p = 0.00215, frequency = 53.6%) was overtransmitted which suggests that GABRB2 is in linkage disequilibrium with schizophrenia in the Chinese Han population. The difference between the two studies may be due to the respective analytic power of the two designs. These two independent studies highlighting linkage disequilibrium support the potential involvement of GABRB2 or a nearby gene in the genetic etiology of schizophrenia.