studies, Li and colleagues (2011) reported that the association between rs1229984 and alcoholism is highly significant (P < 10−30) in Asian populations. Although the rs1229984 variant is common in populations of Asian descent, it is found infrequently (i.e., in less than 5 percent of individuals) in populations of European or African descent. Bierut and colleagues (2012) recently genotyped and determined the influence of this variant in three large European and African American case–control studies. The results indicated a strong protective effect of rs1229984 for alcohol dependence (P = 6.6 × 10−10). The allele also was strongly associated with lower alcohol consumption, defined as the maximum number of drinks consumed in a 24-hour period (P = 3 × 10−13). Thus, although rs1229984 is rare among European and African populations, at an individual level the effect of this ADH1B variant on amount of alcohol consumed and on the risk of developing alcohol dependence is the same regardless of ethnicity.
