Previous evidence also supports a role for epistasis in determining alcohol behavior. A study of Taiwanese Han showed evidence for epistasis between class 1 ADH haplotypes and ADH7 genotypes in predicting alcohol dependence (Osier et al., 2004). Although we found no evidence for interaction between class 1 ADH SNPs and ADH7, there was evidence for interaction between ADH7 and ALDH1A1 SNPs.
