Single nucleotide polymorphisms (SNPs) have been identified at the ADH1B and ADH1C loci with translation of the resulting isoforms having different catalytic efficiencies for ethanol (113, 120) (Figure 6). Further, the ADH1B alleles appear with different frequencies in different racial groups (summarized in (120, 167)). The ADH1B*1 form predominates in Caucasian ancestry and African ancestry populations, and ADH1B*2 predominates in East Asian populations (e.g., Chinese, Japanese, Korean). It is also found in about 25% of Caucasians with Jewish ancestry. The ADH1B*3 form is found in about 25% of individuals of African ancestry. For the ADH1C polymorphisms, ADH1C*1 and ADH1C*2 appear with about equal frequency in Caucasian ancestry groups, but ADH1C*1 predominates in African ancestry and East Asian populations.
