Moreover, we did not observe any correlation between DAT-SPECT values and the motor clinical severity, as measured by MDS-UPDRS-III, in PD (Curran-Everett, 2000, Hua and Lenz, 2005, Boecker et al., 2010) and ET patients (Bologna et al., 2020). Here, SLC6A3 is linked to Parkinson disease.