,21,28,29 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, α-syn SAA kinetic parameters, and disease progression in sporadic, LRRK2, and GBA PD. This evidence concerns the gene LRRK2 and Parkinson disease.