in a meta-analysis; however, in the absence of rs3778150-C, the rs1799971-A allele showed no association with heroin addiction in either ancestral group or in a meta-analysis. Therefore, their findings suggested that the association of rs1799971 with heroin addiction was dependent on the presence of the rs3778150-C risk allele. The current study sought to extend this hypothesis to alcohol use phenotypes, and thus examined the relations of these two OPRM1 variants, rs1799971 and rs3778150, with measures of subjective response to alcohol and alcohol consumption.
