Using RT-QuIC, we could recently show that both, PD and DLB patients with severe mutations in the gene glucocerebrosidase (GBA) present with the highest α-Syn seeding activity compared to other genetic forms with known variable (LRRK2) or even sparse Lewy body pathology (Parkin, PINK1)12. Here, GBA1 is linked to Lewy body dementia.