This is the first study to evidence a relation between rs3778150 and measures of alcohol sensitivity and consumption. These findings tentatively suggest that the rs3778150-C allele is associated with a low subjective response to alcohol. It is important to note that rs3778150 and rs1799971 are in modest LD—that is, their genotypes are modestly correlated and not independent. In the study by Hancock et al. (2015), the rs3778150-C minor allele was observed only in the presence of the rs1799971-A allele, which was also the case in the present study. Their findings demonstrated that rs1799971-A was associated with increased risk for heroin addiction only when tested together with rs3778150-C. Similarly, a recent meta-analysis reported a protective effect for rs1799971-G on general substance dependence and DSM-IV alcohol dependence, though the test of the latter phenotype did not achieve statistical significance and did not account for any effects of rs3778150 (Schwantes-An et al., 2016). Although the direction of effect for the associated allele is consistent across these two studies, previous findings implicating rs1799971 in alcohol sensitivity and alcohol use may have inadvertently been capturing
