Quantitative assessment of the association between fibroblast growth factor 20 rs1721100 C/G polymorphism and the risk of sporadic Parkinson's diseases: a meta-analysis.

Fibroblast growth factor 20 (FGF20) is a neurotrophic factor which enhances the survival of rat midbrain dopamine neurons. Genetic variation in FGF20 may influence the risk of occurrence and development in Parkinson's diseases (PD). Many studies have evaluated the association between FGF20 rs1721100 C/G polymorphism and the risk of sporadic PD; however, published data are still controversial. The aim of the present meta-analysis was to evaluate the association of FGF20 rs1721100 C/G polymorphism with susceptibility of PD. The summary odds ratio (OR) with its 95 % confidence interval (CI) was calculated to estimate the association. Five case-control studies with a total of 3,463 sporadic PD cases and 4,606 controls were finally included into this meta-analysis. Neither the basic allele frequencies nor the genotypic distributions of rs1721100 C/G within FGF20 were different between two groups when all studies were pooled into the meta-analysis. Subgroup analysis by ethnicity showed FGF20 rs1721100 C/G polymorphism was significantly associated with increased risk in the heterozygote comparison model (CG versus GG: OR = 0.83, 95 % CI, 0.72-0.95, P = 0.009) in Asians but not in Caucasians. Overall, this meta-analysis suggests that FGF20 rs1721100 C/G polymorphism is associated with sporadic PD in Asians.