Polymorphisms from five genes were genotyped. SNPs rs3811995 (GABRA6; 25.9% [126] = TT, 51.3% [250] = TC, 22.8% [111] = CC) and rs36021 (SLC6A2; 27.3% [133] = TT, 50.3% [245] = TA, 22.4% [109] = AA) were selected from the Addiction Array and genotyped using the Illumina Golden Gate platform (San Diego, CA). The Addictions Array includes 1350 SNPs from 130 genes and 186 Ancestry Informative Markers (AIMs), described in detail elsewhere (Hodgkinson et al., 2008). In particular, SNP rs36021 (SLC6A2) is a tag SNP that captures haplotype information of about 8 Kb in the 5’ region. SNP rs3811995 (GABRA6) located in the 5’ region is in high linkage disequilibrium (r2 = 0.98) with the SNP most studied in the field, rs3219151 (also known as T1521C). SNP rs279858 (GABRA2; 31.8% [155] = AA, 49.3% [240] = AG, 18.9% [92] = GG) tags a large region previously associated with both alcohol and risk behaviors (Villafuerte, Strumba, Stoltenberg, Zucker, & Burmeister, 2013), which was genotyped by TaqMan (Villafuerte et al., 2012). Genotyping of the DRD4 48 bp variable number of tandem repeat
