SNCA and Parkinson disease: Although the disease etiology remains to be clarified, proteins of PD-causing genes such as SNCA, parkin RBR E3 ubiquitin protein ligase (PRKN), DJ1 (parkinsonism associated deglycase, PARK7), PTEN induced kinase 1 (PINK1) and leucine rich repeat kinase 2 (LRRK2) are involved in the oxidative stress pathway that contributes to the neurodegeneration of PD [8,9].