The minor allele of rs1229984 in ADH1B gene was previously shown to be protective against alcohol dependence in Asian samples, in which this allele is common (Chen et al. 1999; Edenberg 2007; Thomasson et al. 1991; Wang et al. 2012b). We have shown that the minor allele is also protective for excessive alcohol consumption in European Americans and African Americans (Bierut et al. 2012). We therefore performed a conditional analysis and subsequent meta-analysis in the SAGE and COGA datasets, including rs1229984 genotype as a covariate. Because this SNP has a low minor allele frequency and is hard to impute, this SNP was directly genotyped in the SAGE and COGA datasets (Bierut et al. 2012).
