PCSK1N and Parkinson disease: The development of α-syn SAAs has transformed our ability to detect α-syn seeds and diagnose PD.7,18 Making use of MDS-UPDRS I and III, MoCA, DAT-SPECT, and baseline α-syn SAA data from the PPMI cohort, we found that there was no statistically significant association between baseline α-syn seeding activity and disease progression in sporadic, LRRK2, and GBA PD.