SLC6A3 and Parkinson disease: Clinical parameters, dopamine transporter-single photon emission computed tomography (DAT-SPECT), and magnetic resonance imaging (MRI) brain volumetrics were analyzed.<h4>Results</h4>The SAA- and matched SAA+ groups had similar motor performance on the Movement Disorder Society Unified Parkinson's Disease Rating Scale-Part III (MDS-UPDRS-III) and similar cognitive performance on the Montreal Cognitive Assessment (MoCA) at baseline.