The core pathological mechanism of PD is the loss of dopaminergic neurons in the substantia nigra (Braak, et al., 2003) and the secondary reduction of dopamine in the basal ganglia (Bloem et al., 2021), which can be reflected by dopamine transporter (DAT) scans (Poewe and Scherfler, 2003). Here, SLC6A3 is linked to Parkinson disease.