ALDH2 and alcohol dependence: A meta- analysis of studies of Asian samples (Luczak et al. 2006a) indicated that having one ALDH2*2 allele was associated with a four- to fivefold reduction in alcohol dependence (OR = 0.22), and having two ALDH2*2 alleles was associated with an eight- to ninefold reduction in alcohol dependence (OR = 0.12).