LRRK2 and Parkinson disease: The study included 82 prodromal donors, including individuals with gene mutations linked to increased risk of developing PD (GBA and LRRK2;n = 27), individuals diagnosed with hyposmia (n = 29), a combination of hyposmia and mutations (SNCA, GBA, or LRRK2, n = 3), individuals diagnosed with RBD (n = 19), or a combination of RBD and hyposmia (n = 4).