Even though the well studied candidate variants in DRD2, ADH1C, OPRM1 and COMT were not significantly associated with alcohol dependence in SAGE, their odds ratios were in the expected direction based on previous candidate gene studies. More specifically, the odds ratio of 0.088 for rs1799971 in OPRM1 supports previous studies that the minor allele variant is protective against alcohol dependence (Bond et al., 1998; Zhang et al., 2006) while the odds ratios greater than 1 for rs1800497 in DRD2, rs698 in ADH1C, and rs4680 in COMT supports previous studies that the minor allele of these variants are more common in alcohol dependent individuals (Blum et al., 1990; Hendershot et al., 2011; Ponce et al., 2008; Thomasson et al., 1991; Tiihonen et al., 1999; Tolstrup et al., 2008). The fact that these odds ratios are in the expected direction but did not pass a threshold of .05 for significance may suggest that these variants have a small contribution to alcohol dependence and this study lacked the power to detect the association.
