Strong evidence of association was found between the ADH1B Arg48His and alcohol abuse and dependence, as well as alcohol-induced medical diseases, in multiple populations, in particular, in Asians, in this meta-analysis. The His allele was highly prevalent in the Asian ethnic populations, particularly in northeast Asians. It was slightly lower in some Chinese aboriginal groups (e.g., Elunchan) but was higher in others (e.g., Atayal and Paiwan). Figure 3 and Table S11 in Supplement 1 show the His48 allele frequencies of by location.These aboriginal groups (e.g., Atayal and Bunun) may to some extent contribute to the significant heterogeneity between the Asian studies. However, the allele frequency was very low in Europeans, Native Americans, and Africans, and thus, the homozygous His/His was not observed at all in some studies of these populations. This constitutes one of the reasons that the association studies, reported by different research groups, produced discrepant or contradictory results. There are some other possible explanations: for example, the His48 allele could (because of LD) be co-inherited with other ADH variants that might affect the risk of alcoholism and which
