SNCA and Parkinson disease: In the late-onset form of the disease, these are the α-synuclein (SNCA) and leucine-rich repeat kinase2 (LRRK2) genes, while in early-onset PD, they are are parkin (PARK2), PTEN-induced putative kinase 1 (PINK1), and oncogene DJ1 (DJ1) [14].