Heritability analysis indicated significant genetic contribution to variation in LR. The estimate of 67% heritability of overall SRE observed in this study was slightly above the range seen in literature. Research studies observed 40–60% heritability when SRE alone was administered (Schuckit, 1999), and 44–60% following alcohol challenge (Heath et al., 1999; Viken et al., 2003; Agrawal et al., 2009). In the present study, SRE measures for individual time frames were not found to be heritable. During a period of regular drinking (SRRD), there was a trend toward heritability (p=0.068), which, perhaps with a larger sample size, may reveal a heritable association of LR with regular alcohol consumption. The observed heritability of LR may be related to the number of genes associated with LR. Preliminary findings that genes located on chromosome 10 were associated with LR (Wilhelmsen et al., 2003; Schuckit et al., 2005c) were further confirmed in a later study by Webb et al. (2011). Webb and colleagues discovered that loci coding for CYP2E1 were highly correlated with LR measured after an alcohol challenge. Kuo and colleagues observed an association
