Association analysis of the paraoxonase-1 gene with Alzheimer's disease

Genetic variants in the paraoxonase (PON) gene cluster, particularly a single C/T promoter polymorphism (rs 705381) in the PON- I gene, have recently been associated with Alzheimer's disease (AD). The T allele, in particular, presents an increased risk for the development of AD. Here, we investigate the potential role of this polymorphism in an Italian case-control population consisting of 306 sporadic AD patients and 275 controls, and also evaluate a possible interaction with the ApoE genotype. No association between the PON- I polymorphism and AD was observed. The T allele frequency was slightly over-represented in AD patients compared to the controls, but this was far from being statistically significant. Our sample was evaluated to have 97.3% power to detect an OR of 2.0 (64.3% power with OR = 1.5) at an ce level of 0.05. No evidence of an interaction between the T risk-allele and the ApoE epsilon 4 allele status and no effect of the PON-1 polymorphism on age at onset was detected. Our results do not support other studies indicating that the PON- I promoter polymorphism plays a major role in AD, suggesting that other large studies are necessary to further elucidate the effect of PON on the development of the disease in the general population. (c) 2006 Elsevier Ireland Ltd. All rights reserved.