In familial PD, several PD-related genes such as SNCA, LRRK2, Parkin, PINK1, ATP13A2, vacuolar protein sorting 35 ortholog (VPS35) and coiled-coil-helix-coiled-coil-helix domain containing protein 2 (CHCHD2) have been identified to directly affect the mitochondria [105]. Here, PRKN is linked to Parkinson disease.