cluster (Edenberg et al., 2006), SNPs in ADH4 were not significant in this GWAS, although 15 SNPs (particularly in the region between ADH1B and ADH1A) were. Genes encoding GABAA receptors continued to provide evidence for association with alcoholism. A SNP in GABRR2 was among those with the smallest p value in this GWAS (6 × 10−5); that SNP was not itself significant in the earlier family study, although other SNPs in the gene were (Xuei et al., 2010). Although GABRA2 has been associated with alcohol dependence (Edenberg et al., 2004) in many samples (Bauer et al., 2007; Covault et al., 2004; Drgon et al., 2006; Enoch et al., 2008; Enoch et al., 2006; Fehr et al., 2006; Lappalainen et al., 2005; Soyka et al., 2008), there was no evidence in this case-control GWAS, although 5 SNPs in GABRG1 were nominally associated with alcoholism, and 11 with early onset (cf Covault et al., 2008). Six SNPs in GABRG3 (Dick et al., 2004) were associated with alcohol dependence in the EA sample, and 17 SNPs in the much smaller AA sample. In GABRA1 (Dick et al., 2006), we found 3 SNPs associated with alcohol dependence and 4 with early onset. Many SNPs
