Alcohol and drug dependence, which are multifactorial and chronic relapsing disorders, constitute major public health problems. The isoenzymes coded by the alcohol dehydrogenase 1B and 1C genes (ADH1B and ADH1C) and aldehyde dehydrogenase 2 gene (ALDH2) metabolize alcohol into acetaldehyde and acetaldehyde into acetate, respectively. The enzyme encoded by ADH1B is a member of the alcohol dehydrogenase family, which metabolize a wide variety of substrates, including ethanol, retinol, other aliphatic alcohols, hydroxysteroids, and lipid peroxidation products. Among the patients with alcohol dependence (AD), alcoholic cirrhosis occurs in around 10%, hepatitis in 10-35%(1), and alcohol-induced pancreatitis in approximately 5%(2). Alcohol dehydrogenase 1B was hypothesized to be an important ethanol-oxidizing enzyme that may alter genetic susceptibility to AD as well as alcoholic liver disease, cirrhosis, and pancreatitis (the latter two are often alcohol-induced diseases)(3).
