PRKN and Parkinson disease: However, ∼5–10% of PD cases are familial (Wood-Kaczmar et al., 2006) and include mutations in the following genes: α-synuclein, parkin (PRKN), leucine-rich repeat kinase 2 (LRRK2), PTEN-induced putative kinase 1 (PINK1), and ATP13A2 (Hardy, 2010).