Association study for Parkinson's disease and a dopamine transporter gene polymorphism (1215A/G)

The dopamine transporter (DAT) may play a role in the pathogenesis of Parkinson's disease (PD) because dopamine-specific neurotoxins are taken into dopaminergic nerve terminals via the DAT. A recent study has demonstrated that a DAT polymorphism in exon 9 (1215A/G) is associated with susceptibility to PD. This finding was not replicated by another study, however. Therefore, the significance of this association was tested using a Chinese sample population consisting of 102 PD patients and 174 controls, together with the association for onset age. Comparing the two groups, neither the genotypic (p = 0.272) nor allelic frequencies (p = 0.209) were statistically different. Further, the mean onset age was not significantly different for PD patients comparing the DAT genotypes (p = 0.925). Our findings confirm those of the previous negative report and, taken together, suggest that the DAT polymorphism (1215A/G) does not play a major role in the susceptibility to PD. Other DAT genetic variants, and the association of these variants with PD symptomatology or treatment response, may merit further investigation.