The influence of SLC6A3 and DRD2 polymorphisms on levodopa-therapy in patients with sporadic Parkinson's disease

Objectives The aim of this study was to evaluate a possible relationship between DRD2/ANKK1 (rs1800497) and SLC6A3/DAT1 (rs28363170) gene polymorphisms with the response to levodopa (L-DOPA)-therapy in patients with Parkinson’s disease (PD). Methods One hundred and ninety-five patients with idiopathic PD were investigated. Patients were genotyped for rs1800497 and rs28363170 polymorphisms using PCR-RFLP. Logistic regression was performed to assess the association of polymorphisms with the occurrence of the chronic complications of L-DOPA therapy. Key findings Our results showed association between the occurrence of dyskinesia with an increased greater disease severity (P = 0.007), higher L-DOPA dose (P = 0.007) and use of dopamine agonist (P = 0.020). Moreover, there were significant protective effects for age (P = 0.004) and male subjects (P = 0.006). Conclusions Clinical and demographic characteristics of Brazilian PD patients and differences in DRD2 and DAT1 genes may to determine individual variations in the therapeutic response to L-DOPA in the Brazilian PD patients.