We used the Illumina Addiction biology SNP array designed by Hodgkinson et al (Hodgkinson et al., 2008). The panel includes SNPs from 130 candidate genes for alcoholism, addictions and disorders of mood and anxiety and is genotyped using the Illumina GoldenGate platform. Twelve SNPs from GABRA2 were included in the panel. Three SNPs (rs10008315, rs9291283 and rs7678520) that were rare or had low call rates were excluded. In addition, we included two GABRA2 SNPs, rs279826 (intron 4) and rs279858 (exon 5, K132K), genotyped by Taqman (Villafuerte et al., 2012) previously associated with both alcohol measures and impulsiveness (Villafuerte et al., 2012). We included duplicates (78 for the array and 12 for the Taqman assay) and no discrepancies were observed. In summary eleven SNPs are reported in the analyses.
