DRD3 and Parkinson disease: Furthermore, from the known mutations in PD, PRKN, PINK1, NFE2L2, A2M, and PARK7 genes (mitochondrial, oxidative genes and neuro-inflammation) (Krüger et al., 2000; Klein and Westenberger, 2012; Lin and Farrer, 2014; Todorovic et al., 2015) and other genes like DRD3 (Hassan et al., 2016) and HNMT (Yang X. et al., 2015) were showed to be associated with EOPD.