Relationship between the FAS gene A-670G polymorphism and Alzheimer's disease: a meta-analysis

The pathogenetic mechanism of Alzheimer's disease (AD) is still unknown; however, gene polymorphism may play a critical role in the pathogenesis of AD. The aim of this meta-analysis was to evaluate the association between FAS gene A-670G polymorphism and AD.

We searched all related subjects in PubMed, Embase, Cochrane Library, SinoMed, and the China Knowledge Resource Integrated Database and identified seven studies reporting a relationship between the A-670G polymorphism in the FAS gene and AD.

A total of 1512 cases and 1707 controls were included in the seven studies. The meta-analyses results suggested no significant association between the A-670G polymorphism and AD in any genetic models. When a subgroup analysis was conducted by ethnicity, the A-670G polymorphism was also not relevant to AD. However, when stratified by age, the GG genotype increased the risk of early-onset AD. We also found that the A-670G polymorphism was related to patients with AD who carried the apolipoprotein-E ε4 allele in three genetic models.

To sum up, our data suggested that the FAS gene A-670G polymorphism may not be associated with AD. When a subgroup analysis was conducted by ethnicity, the A-670G polymorphism was also not related with AD in Asian and Caucasian population. However, the FAS-670 GG genotype may increase the risk of AD in the younger population (age, ≤65 years). Furthermore, we found that the A-670G polymorphism was related to patients with AD who carried the APOE4 allele in dominant, allele and homozygous models.