PRKN and Parkinson disease: A growing body of evidence shows that dysfunction of synaptic vesicle recycling is involved in the pathogenesis of Parkinson’s disease (PD).18 Studies in both monogenic and sporadic parkinsonism have revealed that proteins encoded by specific PD-causing (SYNJ1, SNCA, PRKN) and PD-associated genes (LRRK2, SH3GL2) are involved in key steps of synaptic vesicle recycling and its regulation.19-21 Disruption of synaptic vesicle membrane traffic affects synaptic transmission, autophagy and the endolysosomal system and causes axon degeneration and ultimately dopaminergic neurodegeneration.18,22