The second ALDH gene, ALDH1A1, appears to play a lesser role in acetaldehyde metabolism relative to ALDH2, but a growing number of studies suggest that this gene contains one or more polymorphisms that influence alcohol related phenotypes in Native American populations. One of the earliest reported results involved a 17 base-pair (bp) deletion in the promoter region of ALDH1A1 commonly referred to as the ALDH1A1*2 allele. Similar to the reports for ALDH2 in Far East Asian populations, this allele has been associated with a reduced risk of alcohol dependence, reduced alcohol consumption, and reduced risk of cigarette smoking [50]. Additional polymorphisms in ALDH1A1 have shown relations with alcohol dependence in the Southwest American Indian and Plains Indian populations [45] and Caucasian [51] populations. Thus, ALDH1A1 represents an interesting candidate gene with respect to alcoholism in several populations including Native Americans.
