SLC6A3 and Parkinson disease: However, the indirect effect of amyloid on the UPDRS Part III score through the mediation of DAT availability in the anterior putamen (indirect effect, B = 4.713; 95% CI, 1.331–7.886; Figure 2C) and posterior putamen (indirect effect, B = 2.744; 95% CI, 0.299–5.936; Figure 2D) was significant in the PD group.