LRRK2 and Parkinson disease: Accumulated genetic analyses have identified that several gene mutations are associated with an early onset of parkinsonism, including α-synuclein (SNCA), (PARK1 and PARK4), Parkin (PARK2), PTEN-induced kinase 1 (PINK1) (PARK6), DJ-1 (PARK7), leucine rich repeat kinase 2 (LRRK2) (PARK8), ATP13A2 (PARK9), HtrA2/Omi (PARK13), PLA2G6 (PARK14), VPS35 (PARK17), coiled-coil-helix-coiled-coil-helix (CHCH) domain 2 (CHCHD2) (PARK22) [3,11].