The PaSS U19 seeks to understand and characterize the preclinical/prodromal phase of a-synucleinopathies. The study will recruit a cohort of iRBD subjects and follow them if/until they convert to PD, LBD, or MSA, using standardized psychometric tests, clinical/neurological evaluations, and diagnostic procedures. PaSS will identify changes associated with the earliest manifestations of a-synucleinopathy disease, including biomarkers of disease progression and potential surrogate endpoints. Biomarkers of a-synucleinopathy burden may range from neurophysiology, to changes in biofluid/tissue, to neuroimaging changes. The eventual goal is to find neuroprotective interventions for a-synucleinopathies.

Applicants should make use of existing infrastructure developed by NIH and advocacy organizations to study Alzheimer’s disease, Alzheimer’s disease-related dementias, and Parkinson’s disease. Data and biosamples collected by PaSS should be readily harmonized with existing data and biosample repositories. Applicants are encouraged to establish collaborations with the Alzheimer’s Disease Research Centers ( and the Michael J. Fox Foundation’s Parkinson’s Progression Markers Initiative (PPMI) (, as well as worldwide collaborations between academic, government, and industry investigators.