The involvement of COMT Val158Met SNP in the susceptibility of PD was detected in Asian populations (Chuan et al., 2015; Kiyohara et al., 2011) and of COMT Val108Met SNP (L/L genotype) in younger subjects and in women among US patients with both parents of European origin (Goudreau et al., 2002). This evidence concerns the gene COMT and Parkinson disease.