Contrary to our expectations, neither the GAD1 nor the GAD2 genes exhibited significant associations with AD after the significance level was adjusted to control for false discoveries. Other than two previous reports for the associations of GAD1 and GAD2 in Han Taiwanese men (Loh et al., 2006) and GAD2 in Russian men (Lappalainen et al., 2007), the current study is the first to include both male and female subjects with relatively larger sample size to examine the associations of AD and several relevant alcohol-related traits with the two GAD genes in a sample from Ireland that is culturally and genetically homogeneous. In different populations, allele or genotype frequencies may exhibit variation across ethnic groups that will influence genetic associations. For GAD1, one marker (rs701492) in Loh et al. (2006) report was also genotyped in our sample with very similar MAF in both studies (In Loh's Taiwanese and our Irish samples: case = 0.29, control = 0.32). However, this marker exhibited genotypic difference (P = 0.01) between their male AD cases and controls, but did not show such difference (P =
