Association of BACE1 gene polymorphism with Alzheimer's disease in Asian populations: meta-analysis including Korean samples.

Background: Beta-site amyloid precursor protein cleaving enzyme (BACE) is a candidate risk factor for Alzheimer's disease (AD) from its key role in beta-amyloid generation. Previous genetic association studies of BACE1 gene have yielded conflicting results. This study is an attempt to clarify whether the common SNP in exon 5 of BACE1 (rs638405, Val262) is associated with a risk for late-onset AD.

Methods: We genotyped a synonymous C/G polymorphism of BACE1 located in exon 5 and apolipoprotein E (ApoE) in 248 AD patients and 224 healthy persons. A meta-analysis with pooled data from four Chinese studies and our results was performed.

Results: The allele and genotype frequencies of BACE1 polymorphism were not significantly different between cases and controls (p > 0.05) in the Korean population. A meta-analysis of previously published Asian populations including Koreans showed evidence of a weak association (p = 0.0555 for genotypes, p = 0.0352 for alleles). However, a significant association between the CC genotype and AD was observed in the ApoE-epsilon4-positive groups (p = 0.0044, OR = 1.995; 95% CI = 1.319-3.018).

Conclusion: These data suggest that BACE1 polymorphism in exon 5 influences risk for late-onset AD in those carrying the ApoE epsilon4 allele.