Familial PD is associated with mutations in many genes including: SNCA (α-synuclein) [94], PRKN (parkin) [95], PARK7 (DJ-1) [96], LRRK2 (leucine-rich repeat kinase 2) [97], and PINK1 (phosphatase and tensin homologue (PTEN)-induced kinase 1) [98]. Here, PRKN is linked to Parkinson disease.