SLC6A3 and red-green color blindness: Dopamine transporter (DAT) imaging is used to detect dopaminergic deficit in striatum to support the diagnosis of Parkinson’s disease (PD) and atypical parkinsonian syndromes, i.e., progressive supranuclear palsy (PSP), multisystem atrophy (MSA), corticobasal degeneration (CBD), and dementias with Lewy bodies.