Note that there is strong evidence of population-specificity for some very important alcohol metabolizing enzyme risk variants, e.g., a nonfunctional ALDH2 variant mentioned briefly above that is confined to certain Asian populations, and an ADH2 variant (rs2066702), traditionally called alcohol dehydrogenase-2*3, which encodes a high-activity isozyme that is common in AAs and rare in European Americans (EAs). Population specificity has been observed, although generally to a lesser degree, at some of the other loci discussed below. Thus it is already clear that risk variants are likely to be differentially important in different populations. Luczak et al. (2006) performed a meta-analysis of the effects of ADH1B (as well as of ALDH2, discussed above) in Asian populations, documenting robust effects on AD risk.
