Catechol-O-methyltransferase Val158Met and the risk of dyskinesias in Parkinson's disease

Background:: The A-allele of the catechol-O-methyltransferase (COMT) Val158Met polymorphism is associated with decreased enzymatic activity and higher dopamine availability. Methods:: We studied 219 patients with PD who were free of dyskinesias at baseline and underwent thorough annual examinations. Results:: The A-allele of the COMT Val158Met polymorphism was related to an increased risk of developing dyskinesias during follow-up, in a dose-dependent manner (adjusted hazard ratios for the AG and AA genotypes [compared to GG]: 2.09 [95% confidence interval (CI), 1.07-4.06] and 2.81 [CI, 1.43-5.54], respectively). Conclusions:: This finding suggests that genetic factors may affect susceptibility to dyskinesias in PD.