Association between genetic polymorphism of dopamine transporter gene and susceptibility to Parkinson's disease

OBJECTIVE: To explore the association between genetic polymorphism of dopamine transporter (DAT) gene and susceptibility to Parkinson's disease (PD). METHODS: The polymorphism of DAT 3' VNTR was analyzed in 171 PD patients and 180 unrelated healthy controls with amplification fragment length polymorphism (Amp-FLP). RESULTS: Five alleles of the DAT 3' VNTR were detected, consisting of 7, 8, 9, 10 and 11 copies of the 40 bp repeated sequence. The 10-copy allele was the most common one in both patients and controls. There were significant differences in both allelic and genotypic distributions of the DAT 3' VNTR between the patient and control groups (P = 0.016, P = 0.03, respectively; Fisher's exact test). The frequency of the 11-copy allele was significantly higher in patients (4.4%) than in controls (1.1%), with an odds ratio of 4.08 (95% confidence interval 1.25 approximately 14.7, P = 0.008). CONCLUSION: DAT 3' VNTR 11-copy allele is a genetic factor susceptible to PD in the population tested.