Fourteen single nucleotide polymorphisms (SNPs) across the GABRA2 locus were selected on the basis of previous work completed by our group (Lind et al., 2008). Briefly, 41 SNPs within or flanking GABRA2 were genotyped in an independent Australian twin sample (Alcohol Challenge Twin Study) that completed an alcohol challenge test (Martin et al., 1985). The 41 SNPs were selected on the basis of data available at the time from (1) association studies (e.g., Covault et al., 2004; Edenberg et al., 2004; Pierucci-Lagha et al., 2005) and (2) the International HapMap Project public database (http://www.hapmap.org/; Phase II dbSNP Build 124). Linkage disequilibrium data from this study indicated that a reduced set of fourteen haplotype-tagging SNPs would provide appropriate coverage (r2 ≥ 0.95) of GABRA2. Three SNPs (rs279871, rs279836, rs497068) failed during the assay design or provided unreliable genotype data and were excluded. The locations of the eleven remaining SNPs typed in the study are shown in Figure 1 and SNP information, including the observed minor allele frequency (MAF), is described in Table 2.
