SLC6A3 and Alzheimer disease: The pattern of differences between RBD subgroups with normal, borderline, and abnormal DAT-SPECT were not altered after excluding the AD+ subgroup from the analysis, i.e. trend towards higher mean MDS-UPDRS-III score and higher prevalence of objectively measured orthostasis was shown in patients with abnormal compared to normal/borderline DAT-SPECT (Supplementary Table 7).