Association between a T/C polymorphism in intron 2 of cholesterol 24S-hydroxylase gene and Alzheimer's disease in Chinese.

A polymorphism (T/C) in intron 2 of the cholesterol 24-hydroxylase (CYP46) gene has recently been reported to be associated with the risk for late-onset Alzheimer's disease (LOAD). To investigate possible involvement of the CYP46 gene and apolipoprotein E (APOE) gene polymorphisms in the manifestation of LOAD, we analyzed 99 sporadic LOAD patients and 113 healthy controls of China. We found an obvious association between CYP46 TT genotype and LOAD (OR = 2.98, 95% CI 1.64–5.44, P < 0.001). A clear increase of the risk to develop LOAD was also observed in subjects carrying both the CYP46 TT genotype and the APOE ɛ4-allele (OR = 12.94, 95% CI 4.26–39.32, P < 0.001). Our data reveal that the polymorphism of CYP46 intron 2 is implicated in the susceptibility to LOAD and a strong synergistic interaction between CYP46 TT homozoygots and APOE ɛ4 carrier status on the risk of LOAD.