SLC6A3 and Parkinson disease: Dopaminergic degeneration is detectable early with multimodal brain imaging, suggesting some striatal territories are affected decades before diagnosis.1,2 Individuals with prodromal PD have increased nigral iron deposition on susceptibility MRI and accelerated dopaminergic dysfunction on serial dopamine transport (DAT) scanning.3,4 However, brain imaging for diagnosis and disease monitoring in PD is limited as a scalable resource.