With respect to medications within the PD patients, 22(59.5%) were treated with levodopa, 7(18.9%) with dopamine agonist, 9(24.3%) with MAO-B inhibitor, 9(24.3%) with amantadine, 6(16.2%) with artane, and only 1(2.7%) with COMT inhibitor. This evidence concerns the gene COMT and Parkinson disease.