SLC6A3 and Parkinson disease: Comparable striatal 18F-flurodopa (FDOPA) binding and reduced DAT-SBRs were observed in N = 25 LRRK2-NMCs compared to N = 35 healthy controls; however, these observed levels in the NMC groups were significantly higher than those of LRRK2-PD [56] The authors of this study speculated that this finding might be representative of a primary effect on DAT function where preserved FDOPA can persist up to symptom onset [50].