PRKN and Parkinson disease: Although most PD cases occur sporadically, mutations in several genes, such as SNCA (α-synuclein), PARK2 (parkin), DJ-1, PINK1, ATP13A2, VPS35 (vacuolar protein sorting 35), EIF4G1 (eukaryotic initiation factor 4G1) and LRRK2 (leucine-rich repeat kinase 2), have been identified in hereditary PD (Tsika and Moore, 2013).