DDRGK1 and Parkinson disease: For example, suppose a PD-RBD patient scored 15 on the UPSIT, with a mean putamen DAT signal of 1, a putamen asymmetry index of 20 on DAT imaging, a p-tau/α-syn value of 0.5 and a p-tau level of 10 pg/ml in CSF, and had the G/G genotype of DDRGK1 rs55785911.