Apolipoprotein E gene polymorphism in Indian patients with Alzheimer's disease and vascular dementia.

The association of apolipoprotein E (ApoE) gene polymorphism with Alzheimer's disease (AD) has been reported in several populations including one from a rural community in North India. However, the association of ApoE polymorphism with vascular dementia (VaD) is yet to be established in this population. In a case-control study involving 54 cases of dementia (29 AD and 25 VaD) and 76 age-matched healthy controls, the frequency of epsilon4 allele was significantly higher among cases of AD and VaD compared with controls (p < 0.001). The epsilon3epsilon3 (p < 0.05) and epsilon2epsilon3 (p < 0.001) genotypes were found to be protective. The odds of developing AD or VaD were 4.4 and 3.7 times higher, respectively, in the presence of even a single epsilon4 allele. Our results suggest that the increased risk of developing AD or VaD is similar among Asian Indians with ApoE epsilon4 compared with the Caucasian population.