Association of rs356219 and rs3822086 polymorphisms with the risk of Parkinson’s disease: A meta-analysis

•We performed the first meta-analysis to assess the rs356219 and rs3822086 polymorphism of SNCA in PD.•The SNCA rs356219 polymorphism was associated with the risk of PD in overall populations.•The subgroup analysis showed SNCA rs356219 may increase the risk of PD in Asian and Caucasian populations respectively.•SNCA rs3822086 polymorphism may increase the risk of PD in Asian populations. Numerous case-control studies have investigated the relationship between rs356219 and rs3822086 polymorphisms and Parkinson's disease (PD) susceptibility. However, these publications have obtained contradictory results. In this study, we conducted a meta-analysis to evaluate the possible association between the two polymorphisms and PD. Literature searches were conducted on PubMed, Web of Science, EMBASE, CNKI and the Wanfang database on studies published until March 2019. Authentic data were calculated utilizing STATA 12.0 statistics software on the data provided in each study. The genetic association between SNCA polymorphisms and the risk of PD was evaluated using the pooled odds ratios (OR) and 95% confidence interval (CI). The results indicate that there is a significant association between rs356219 polymorphism and PD susceptibility for all genetic models (allelic: OR = 1.377, 95% CI: 1.275–1.487, p = 0.000; homozygous: OR = 1.958, 95% CI: 1.666–2.301, p = 0.000; heterozygous: OR = 1.261, 95% CI: 1.158–1.373, p = 0.000; dominant: OR = 1.431, 95% CI: 1.320–1.550, p = 0.000; recessive: OR = 1.632, 95% CI: 1.431–1.861, p = 0.000), which is consistent with the results of the subgroup analyses on Asians and Caucasians. In addition, rs3822086 polymorphism was found to be related to PD in the allelic (OR = 1.249, 95% CI: 1.099–1.419, p = 0.001), homozygous (OR = 1.479, 95% CI: 1.142–1.915, p = 0.003), heterozygous (OR = 1.292, 95% CI: 1.033–1.615, p = 0.025) and dominant (OR = 1.331, 95% CI: 1.030–1.719, p = 0.029) models. Therefore, our results suggest that the presence of SNCA rs356219 and rs3822086 variants may increase the risk of PD.