Association between dopamine receptor D2 TaqIA polymorphism and Parkinson disease risk: a meta-analysis

Although many publications have evaluated the correlation between dopamine receptor D2 (DRD2) TaqIA polymorphism and Parkinson disease (PD), the results remain inconclusive. In order to further address the association between DRD2 TaqIA polymorphism and PD risk, we performed a meta-analysis of all eligible studies from more databases. Related studies were identified from six databases involving PubMed, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure (CNKI), and Chinese Biology Medicine (CBM) through Octorber 2018. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. A total of 13 studies including 3558 PD patients and 10186 controls were involved in this meta-analysis. Overall, no significant association was found between DRD2 TaqIA polymorphism and PD risk in the total population. A further subgroup study by ethnicity showed a significant association between DRD2 TaqIA polymorphism and PD in Caucasians (for A1 vs. A2: P=0.02, OR=1.14, 95% CI: 1.02-1.27; for (A1A1 + A1A2) vs. A2A2: P=0.03, OR=1.16, 95% CI: 1.02-1.33). No significant results were observed in Asians. In conclusion, this meta-analysis provides evidence that DRD2 TaqIA polymorphism may contribute to the PD development in Caucasians, and large-scale well-designed studies are required in future to confirm this conclusion.