SNCA and Parkinson disease: There are several genes responsible for inherited PD, but five widely accepted genes responsible for late-onset are a-synuclein (SNCA), and leucine-rich repeat kinase 2 (LRRK2), whereas, for early onset, Parkin (PARK2), oncogene DJ1, and PTEN-induced PINK1 are important (Coppede, 2012).