The association of mitochondrial aldehyde dehydrogenase gene (ALDH2) polymorphism with susceptibility to late-onset Alzheimer's disease in Chinese

A functional polymorphism of mitochondrial aldehyde dehydrogenase gene (ALDH2 1/2 polymorphism) can influence the accumulation of acetaldehyde which may have a role in Alzheimer's disease (AD), and is widely prevalent among Mongoloids. Therefore ALDH2 1/2 polymorphism may represent a good candidate for genetic risk factors for AD, especially in East Asian. A case-control study from Japan found that ALDH2⁎2 was associated with late-onset AD (LOAD), interacting synergistically with the presence of the apolipoprotein E allele 4 (APOE ε4). But the subsequent studies in Koreans didn't find the similar result. To determine whether the ALDH2 gene 1/2 polymorphism contributes to the risk for LOAD in Chinese, we have investigated 188 sporadic LOAD patients and 223 healthy controls from Chinese. A significantly increased risk of AD in the carriers of ALDH2⁎2 allele (OR = 3.11, 95% CI 2.06–4.69, P < 0.001) was observed.After stratifying by APOE ε4 status, increased LOAD risks associated with the ALDH2 2 allele carriers only in the APOE ε4 non-carriers (χ2 = 31.79, df = 1, P < 0.001) and with the 2-allele in either groups (χ2 = 6.64 df = 1, P = 0.0099 and χ2 = 37.38, df = 1, P < 0.001) were seen. These results suggested that the ALDH2 gene 1/2 polymorphism might be a risk factor for LOAD and dependent on APOE ε4 status in Chinese.