DAT is the principal regulator of synaptic DA transmission, and genetic variants in SLC6A3 alter expression, membrane localisation, hDAT density, dopamine reuptake activity, and dopamine neurotransmission dynamics, contributing to a pathophysiological spectrum from infantile to adult-onset parkinsonism-dystonia, termed DTDS. Here, SLC6A3 is linked to SLC6A3-related dopamine transporter deficiency syndrome.