Association of paraoxonase 1 gene polymorphisms with risk of Parkinson's disease: a meta-analysis
Paraoxonase1 (PON1) gene polymorphisms were implicated as risk factors for Parkinson's disease (PD), but the results of case-control studies that investigated these associations were controversial. In order to provide an answer to these contradictory results, a meta-analysis of all available studies relating the PON1-55M/L and PON1-192Q/R polymorphisms to the risk of developing PD was conducted. The racial descent of the populations in these studies was Caucasian and Asian. The meta-analysis revealed that there was an association of the PON1-55M allele and the risk of developing PD relative to the L allele: fixed effects pooled odds ratio (OR) 1.32 [95% CI (1.10-1.59)]. In addition, there was evidence of association for the genotypic contrast PON1-55MM+LM relative to PON1-55LL: fixed effects OR = 1.50 [95% CI (1.16-1.95)]. There was no significant association between PON1-192Q/R alleles and risk of developing PD: OR = 1.09 [95% CI (0.93-1.26)]. There was no evidence for an association between the genotypic contrasts of PON1-192 and development of PD. The heterogeneity between studies and the publication bias were not significant (P greater than or equal to 0.10) in either polymorphism. Therefore, the pooled results of the meta-analysis supported that there was an association between PON1-55M/L polymorphism and PD and that PON1-192Q/R polymorphism was unlikely to be a major risk factor for susceptibility to PD.