Presynaptic nigrostriatal dopamine transporter (DAT) imaging that has a high sensitivity for the diagnosis of PD shows variable results in MSA, PSP, and CBD (sensitivity 100%, 97.6%, 93.2%, and 60%, respectively), indicating that abnormal DAT scans may have a relatively low specificity in the differential diagnosis of APs [163]. This evidence concerns the gene SLC6A3 and multiple system atrophy.