The etiology of alcohol use disorders (AUDs; alcohol abuse and dependence) is complex, with approximately 50 to 60% of the risk being attributed to genetic factors (Heath et al., 1997; Prescott et al., 1999). Polymorphic genes, including the aldehyde dehydrogenase gene ALDH2 (12q24) and the alcohol dehydrogenase gene ADH1B (4q22), have been proposed as particularly compelling alcohol-specific genes associated with AUDs (Li, 2000).
