The 4q23 region, which contains the genes for several alcohol metabolizing enzymes, has been associated with multiple alcohol use behaviors. This association is one of the most consistently replicated findings in the field of psychiatric genetics, although the effects are clearly ancestry-specific (7). There appear to be multiple signals in this region, including ADH1C (17, 18, 21–24), ADH4 (18), ADH5 (21, 23) and the METAP1/EIF4E region (21–23). The GSCAN consortium recently showed that there are at least 13 independent signals with minor allele frequencies over 0.001 at 4q23 (21). Intriguingly, several of those loci are also strongly implicated in non-psychiatric, somatic traits (25).
