Polymorphisms in neprilysin gene affect the risk of Alzheimer's disease in Finnish patients

Objectives: Neprilysin (NEP) is an amyloid beta-peptide (Abeta) degrading enzyme expressed in the brain, and accumulation of Abeta is the neuropathological hallmark in Alzheimer's disease ( AD). In this study we investigated whether polymorphisms in the NEP gene have an effect on the risk for AD. Methods: The frequencies of seven single nucleotide polymorphisms ( SNPs) and apolipoprotein E ( APOE) were assessed in 390 AD patients and 468 cognitively healthy controls. Genotypes of the study groups were compared using binary logistic regression analysis. Haplotype frequencies of the SNPs were estimated from genotype data. Results: Two SNPs, rs989692 and rs3736187, had significantly different allelic and genotypic frequencies (uncorrected p = 0.01) between the AD and the control subjects and haplotype analysis showed significant association between AD and NEP polymorphisms. Conclusion: Taken together, these findings suggest that polymorphisms in the NEP gene increase risk for AD and support a potential role for NEP in AD.