In conclusion, our similar results in two independent populations, Plains Indians and Finnish Caucasians, have identified a complex situation: (a) GABRG1 haplotypes and SNPs are significantly associated with AUD; (b) GABRA2 haplotypes are not associated with AUD except, as previously shown (Enoch et al, 2006a), when mediated by trait anxiety; (c) there are three common ancestral haplotypes that span GABRG1 and GABRA2; their association with AUD is determined by GABRG1 (d) in the Finns, the association of three less common (< 0.05) long-distance haplotypes with AUD is determined by GABRA2. Our results suggest that there are likely to be independent contributions from both GABRG1 and GABRA2 to the risk for AUD.
