Striatal dopamine transporter (DAT) imaging can be used in the differentiation of degenerative parkinsonian disorders from conditions without such degeneration.1,2 Early to moderate Parkinson disease (PD) patients typically have a clear 50% to 60% loss in putaminal DAT binding compared with healthy individuals.3 However, several drugs that affect dopaminergic neurotransmission can influence the imaging outcome, thus biasing the interpretation. Here, SLC6A3 is linked to Parkinson disease.