With the presence of amyloid, the anterior putaminal DAT availability further decreased from 3.61 to 2.69 (B = −1.12, Q = 0.016), and the posterior putaminal DAT availability decreased from 3.32 to 2.28 (B = −1.20, Q = 0.016) in the PD group. The gene discussed is SLC6A3; the disease is Parkinson disease.