As shown in Table 3, there were no significant genotype differences on drinking behavior and level of response to alcohol for SNP rs1391166. However, analyses of SNP rs1497571 revealed that individuals who were homozygous for the C allele, reported requiring a higher number of drinks to obtain alcohol effects at 3 months of regular drinking [SRE-3; t(120) = 2.18, p < 0.05], during a period of heaviest drinking [SRE-H; t(120) = 2.12, p < 0.05], and the SRE total score [SRE-T; t(120) = 2.35, p < 0.05]. Likewise, there was a trend toward a significant genotype effect on SRE scores for the first 5 times participants drank alcohol [SRE-5; t(120) = 1.82, p = 0.071]. These results suggest that carriers of the T allele of SNP rs1497571 of the GABRG1 gene are high responders to alcohol. Follow-up analyses breaking down this genotype group and comparing the TT (n = 18) and CT (n = 71) groups revealed no significant group differences on level of response to alcohol (p > 0.10), which did not support a T allele gene dose effect.
