An association study between genetic variants at mu-opioid receptor, dopamine transporter, catechol- O-methyltransferase, and dopamine genes and risk of Parkinson’s disease

Background: Parkinson’s disease (PD) is a complex disorder that involves multiple genetic and environmental factors. Several candidate genes have been speculated to be involved in the development of PD. We conducted a case-control study to investigate the association between PD and single nucleotide polymorphisms (SNP) at the OPRM1, DAT, COMT and DRD2 genes in a Taiwanese population. Methods: The study included 260 PD cases and 100 healthy controls. SNPs at OPRM1 (rs1799971), DAT (rs2652510 and rs2550956), COMT (rs4680) and DRD2 (rs1800497) were determined by high-resolution melting (HRM) analysis using a LightCycler®480 instrument. Each genotype was confirmed by direct sequencing. The genotype was checked for Hardy-Weinberg equilibrium. Results: The chi-square test (χ2) was used to examine the association between SNP genotypes and PD. The OPRM1 (rs1799971), DAT (rs2652510 and rs2550956), COMT (rs4680) and DRD2 (rs1800497) polymorphisms showed no association with PD. Notably, an additional meta-analysis indicated that DAT rs2652510 was significantly associated with PD risk. Conclusions: In the Taiwanese population the frequency of the OPRM1, DAT, COMT, and DRD2 genotypes exhibits no difference between the PD patients and normal controls. The meta-analysis of the original and available data from published studies resulted in significant p values <0.01 for DAT rs2652510. Neurology Asia 2013; 18(3) : 279 – 287