LRRK2 and Parkinson disease: Mutations in the genes of α-synuclein (SNCA), leucine-rich repeat kinase 2 (LRRK2), PTEN-induced putative kinase 1 (PINK1), parkin RBR E3 ubiquitin-protein ligase (PARK2), and cytoplasmic protein sorting 35 (VPS35) are associated with PD.