PRKN and Parkinson disease: Mutations in PARK2 (Parkin) and PARK6 (PINK1) have been independently linked to familial cases of Parkinson's disease, associating defects in mitophagy with the degeneration of dopaminergic neurons, a major feature of Parkinson's disease (Pikrell and Youle, 2015; Springer and Macleod, 2016).