PRKN and Parkinson disease: To date, a number of early‐onset genetic forms of PD (Parkin, PINK1, and DJ‐1)1, 2, 3 and complex parkinsonism syndromes (ATP13A2, PLA2G6, FBXO7, SLC6A3, SLC39A14, and PANK2) have been described.4, 5, 6, 7, 8, 9 Importantly, the study of such monogenic forms of disease have provided significant insight into the pathogenic mechanisms underlying sporadic PD.10 More recently, two genes, namely SYNJ111 and DNAJC6,12, 13, 14 encoding proteins involved in postendocytotic recycling of synaptic vesicles, have been identified in early‐onset parkinsonism.