SLC6A3 and Parkinson disease: Our results add several points to this ongoing discussion: i) prodromal PD probability is higher in patients with abnormal DAT-SPECT (even when DAT-SPECT item is excluded from the calculation) suggesting more advanced neurodegeneration in this subgroup and indicating that calculation of prodromal PD probability may be helpful in stratification of the RBD cohort, ii) when RBD status is excluded from the calculation, positive DAT-SPECT status is the crucial factor for fulfilling MDS prodromal criteria.