Group comparison stratified by CSF α-Syn seeding kinetic tertiles showed that:Patients in the lowest tertile of the LAG (shortest LAG phase) presented with the highest prevalence of cognitive impairment (61% vs. 54% vs. 41%; p = 0.05) and of GBA mutation carrier status (56% vs. 40% vs. 34%; p = 0.032) compared to the mid and highest (longest) LAG tertile groups. Here, GBA1 is linked to Cognitive impairment.