[The relationship between prion protein gene codon 129 polymorphism and Alzheimer's disease].

OBJECTIVE: To examine the relationship between prion protein gene (PRNP) codon 129 polymorphism and Alzheimer's disease (AD) by means of meta-analysis.

METHODS: Odds ratios (OR) of prion protein gene codon 129 genotype distribution in AD patients against healthy control was analysed. All the relevant studies were identified and poor-qualified studies were eliminated. A meta-analysis software, Review Manager 4.2 was applied for investigating heterogeneity among individual studies and summarizing effects across studies.

RESULTS: A total of 4 studies including 1095 patients and 940 controls were included but with rectification 972 cases and 658 controls of 3 studies were included. No heterogeneity among the studies was found. The pooled Peto OR (with 95% CI) of (MM + VV) vs MV is 1.10 (95% CI 0.89-1.35, P = 0.38), while the pooled Peto OR of V* vs MM is 0.80 (95% CI 0.65-0.98, P = 0.03) and the pooled Peto OR of M* vs VV is 1.38 (95% CI 1.01-1.89, P = 0.04).

CONCLUSION: In European population, PRNP M and V homozygosity is not statistically significantly associated with the onset of AD. M/* genotype is associated with increased risk of AD while V/* genotype is associated with a decreased risk of AD.