Association of CYP46 gene polymorphism with sporadic Alzheimer's disease in Chinese Han populations: a meta-analysis.

It is well known that genetic variants play an important role in the pathogenesis of Alzheimer's disease (AD). Recently, several studies have found that an intronic single-nucleotide polymorphism (SNP) in cholesterol 24S-hydroxylase (CYP46) gene was associated with sporadic AD (SAD). Within the CYP46 gene, the most well-studied SNP that has been found to be associated with an increased risk for SAD in Caucasians is the intronic SNP rs754203. Subsequently, other researchers have attempted to validate this finding in Chinese Han populations. However, these studies have produced both negative and positive results. To derive a more precise estimation for whether an association exists between rs754203 and SAD in the Chinese Han population, we performed the present meta-analysis of six case-control studies published up to July 2012 by searching the Medline, AlzGene, CNKI, and Wan Fang databases. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for four genetic models (allelic model: T vs. C; additive model: TT vs. CC; recessive model: TT + TC vs. CC; dominant model: TC + CC vs. TT) in the six studies, which included a total of 1187 cases and 1283 controls. The statistical analysis showed no significant differences in rs754203 between patients and controls for any of the four genetic models (p > 0.05 for each model). In conclusion, despite several limitations, this meta-analysis indicates that the CYP46 gene SNP rs754203 is not significantly associated with SAD susceptibility in Chinese Han populations.