SLC6A3 and Parkinson disease: Dopamine transporter SPECT imaging using 123I-Ioflupane is useful and safe for differentiating adult patients with suspected Parkinson’s disease (PD) or parkinsonian syndromes (PS) from normal patients or patients with other entities including essential tremor (ET), dystonic tremor, psychogenic parkinsonism or drug-induced parkinsonism [1–7].