PRKN and Parkinson disease: Mitochondrial dysfunctions have been reported in Parkin (PARK2), PINK1 (PARK6)-, DJ-1 (PARK7)-, LRRK2 (PARK8)-, and CHCHD2 (PARK22)-linked familial cases (Park et al., 2018), and several risk variants of these genes have been identified in idiopathic cases of PD (Kalia and Lang, 2015, Nalls et al., 2014).