the ADH1B-3 allele had a protective effect among Southwest American Indians. With regard to ADH1C, there is evidence that the faster metabolism of alcohol (i.e., greater accumulation of acetaldehyde), mediated by the possession of the ADH1C-1 allele, has protective effects (Chen et al. 1999; Choi et al. 2005; Osier et al. 1999). However, these effects are complicated by the fact that the allele is commonly inherited with ADH1B-2 (i.e., these markers are in linkage disequilibrium; LD), making it unclear whether this is an independent effect. In addition, the dynamic and multidimensional nature of these behavioral phenotypes suggest that non-linear models may be required to capture their complexity (Buscema, 1998).
