Background: The association between methylenetetrahydrofolate reductase (MTHFR) gene (rs1801133) 677C/T polymorphism and Alzheimer's disease (AD) is controversial. The objective of the study was to investigate the possible association between MTHFR 677C/T polymorphism and AD.
Method: We performed a meta-analysis pooling data from all relevant studies including 3,299 cases and 4,363 controls. We applied a random-effects or fixed-effects model to combine odds ratio (OR) and 95% confidence intervals (95% CI).
Results: This meta-analysis demonstrated that the MTHFR T allele or dominant model for T allele (CT + TT) had an increased risk for AD in combined populations (OR, 95% CI: 1.13, 1.05-1.21; 1.18, 1.07-1.31, respectively), and a significant association was found in allele contrast, recessive, and dominant model in Asian populations, but not in Caucasian populations.
Conclusion: The MTHFR C677T polymorphism is associated with AD in Asian populations, but not in Caucasians.