Moreover, although striatal DAT binding has been previously reported to be lower in PSP than in PD and MSA (Badoud et al. 2016; Kaasinen et al. 2019), it is unknown whether the difference reflects the pathophysiological differences between diseases, since disease duration and severity were not consistent among the diagnoses in these studies. This evidence concerns the gene SLC6A3 and supranuclear palsy, progressive, 1.