Kranzler, 2004; Enoch, Schwartz, Albaugh, Virkkunen, & Goldman, 2006; Fehr et al., 2006; Lappalainen et al., 2005; Olfson & Bierut, 2012; Soyka et al., 2008). Although there have been failures to replicate (Covault, Gelernter, Jensen, Anton, & Kranzler, 2008; Drgon, D'Addario, & Uhl, 2006; Matthews, Hoffman, Zezza, Stiffler, & Hill, 2007) a recent meta-analysis confirms the evidence for association (Li et al., 2014). In addition, translational research has found the role of GABRA2 in rodent drinking (Dixon, Walker, King, & Stephens, 2012; J. Liu et al., 2011) and in the brain’s response to alcohol-related (Kareken et al., 2010) and monetary reward cues (Villafuerte et al., 2012). While GABRA2 SNPs have not been identified via GWAS, they typically have the lowest p-values of candidate polymorphisms extracted from GWAS data (Olfson & Bierut, 2012). Interaction between GABRA2 and parental monitoring was tested based on the twin literature suggesting that parental monitoring moderates the relative importance of overall genetic effects (as inferred based on comparisons of twins, not using measured genotypes) on substance use outcomes in adolescence (Dick, Pagan, Viken, et al., 2007; Dick, Viken, et al., 2007); genetic effects assumed greater importance under conditions of lower parental monitoring, presumably because adolescents with
