There are multiple ADH and ALDH genes, and many variants of these genes have been examined for their association with alcohol dependence. Most of the studied variants involve changes of single nucleotide polymorphisms (SNPs), in coding and noncoding regions of the DNA. The ADH genes are located in a small region on chromosome 4 (Fig. 1). The ALDH gene associated with alcohol dependence, ALDH2, is on chromosome 12q24.2. This article discusses the major association findings between alcohol metabolism genes and alcoholism. For a more comprehensive review on the genetics of alcohol metabolism, see Edenberg.13
