SLC6A3 and Parkinson disease: We advocate that in adolescents or adults with a clinical picture of juvenile parkinsonism (onset <20 years) investigations for DTDS should be considered, including: (i) CSF neurotransmitter studies; (ii) DAT SPECT scan (abnormal in DTDS) (Kurian et al., 2011a); and (iii) SLC6A3 sequencing.