This study aimed to investigate the association between selected variants of genes related to dopamine metabolism pathways, representative, functional polymorphisms (rs1799836 of MAOB; rs5326 of DRD1; rs2283265, rs1800497, rs1801028, rs1799732, rs1076560 of DRD2, and rs1065852 of DDC), and the risk of and progression of Parkinson`s disease. This evidence concerns the gene MAOB and Parkinson disease.