The genes that are most frequently associated with the pathology of PD are α-sinuclein (SNCA), leucine rich repeat kinase 2 (LRRK2), glucocerebrosidase (GBA), PTEN induced kinase 1 (PINK1), parkin (PARK2), and DJ (PARK7) (Badger et al., 2014). Here, SNCA is linked to Parkinson disease.