Blood Alpha-Synuclein, Gene Expression, and Smell Testing as Diagnostic and Prognostic Biomarkers in Parkinson's Disease

PROBE will test three biomarkers in PD subjects and controls to determine their feasibility and potential utility as markers of risk and prognosis for PD. This is a case control study, in which PD subjects will be compared to neurologically healthy controls and disease controls (MSA and PSP). The blood biomarker samples will be drawn once to evaluate blood alpha-synuclein levels as well as collection of lymphocyte mass for array analysis. Olfaction will be measured using the UPSIT for all subjects. The UPSIT will be conducted as part of PostCEPT for PD subjects and will only be repeated in this study for PD subjects in not done within 6 months. Control subjects may also choose to submit a blood specimen for processing and storage at the Coriell Institute for Medical Research, a research resource supported by the NINDS Human Genetics Resource Center.

Follow-up of the PD population over a 3-year period will allow us to evaluate the prognosis for important motor aspects of PD that will occur frequently in this cohort. These complications of PD include motor complications, postural instability, and non-motor impairment such as cognitive decline.

Healthy and disease control subjects may give permission at the Baseline visit to be contacted and followed in the previously established PSG FOUND study using mail and telephone contact to assess clinical status. Participation in the FOUND study provides another mechanism to maintain contact with subjects and collect supplemental data beyond that collected at the PROBE Baseline visit.