Additionally, the presynaptic region is a known site of action for gene products associated with PD (e.g., auxilin, synaptojanin, α-synuclein).22–25 Despite these observations, the field lacks a unified framework for early dopaminergic synaptic impairments and their contribution to subsequent manifestations of PD, in part due to the limited understanding of the precise mechanisms underlying these deficits. This evidence concerns the gene DNAJC6 and Parkinson disease.