Two studies investigated both AD and alcohol abuse; seven studies had no explicit description of the patients as alcohol dependent (the possibility that subjects with a diagnosis of alcohol abuse could not be excluded); the other studies clearly described the patients as alcohol dependent (these “definite” alcohol dependent patients without any alcohol-induced diseases were designated as “AD” in Table 1). The meta-analysis based on these “definite” alcohol dependent subjects also showed that there was no major change on the significance level of the association. Strong association was still detected in all the combined populations, in particular, in the Asian populations and in the combined Asians and Europeans for both allelic and genotypic analyses. For instance, the allelic P values were 2×10−29 (OR = 2.12 (1.86, 2.42)) and 1×10−33 (OR = 2.28 (1.99, 2.6)) in the combined populations and the Asian populations, respectively (Table 1).
