SLC6A3 and multiple system atrophy: Baseline decreased tracer striatal uptake in iRBD patients when compared with controls, and in PD patients compared with iRBD patients and with controls.After a follow-up period of 5 years 10 iRBD patients converted to neurodegenerative disease (5 PD, 1 MSA, and 4 LBD), and 6 dropped-out from the study. The baseline PD pattern of DAT predicted 58% of disease converters (67% if combined with the presence of hyposmia).