Eight proteins, including granulin precursor, mannan-binding-lectin-serine-peptidase-2,and plasma-protease-C1-inhibitor, were identified in the targetedexperiment as strong predictors for Parkinson’s, and machinelearning models classified 79% of premotor individuals as at riskfor PD up to 7 years before motor symptoms, with 100% accuracy indistinguishing Parkinson’s patients from healthy controls.This panel of blood biomarkers holds promise for early detection ofParkinson’s and could aid in selecting participants for clinicaltrials aimed at preventing or delaying the onset of motor symptoms. This evidence concerns the gene GRN and Parkinson disease.