Dopamine transporter (DAT) imaging is commonly used as a diagnostic tool in PD, as it is sensitive to degeneration of dopaminergic nigrostriatal pathways.27 Striatal DAT decreases in PD as the disease progresses, owing to a loss of presynaptic dopaminergic projections from the substantia nigra and ventral tegmental area. Here, SLC6A3 is linked to Parkinson disease.