["The contribution of genetic variability to clinical heterogeneity in Parkinson's disease is insufficiently understood. We aimed to investigate the effect of cumulative genetic risk on clinical outcomes.", "In a single-center study of 336 patients we genotyped 19 independent susceptibility variants identified in genome-wide association studies of Parkinson's disease. We tested for association between a cumulative genetic risk score and 3 outcome measures: survival, time until progression to Hoehn and Yahr stage 3, and Unified Parkinson's Disease Rating Scale motor score severity.", 'Genetic risk score was significantly associated with time from diagnosis to Hoehn and Yahr stage 3 in a Cox regression model (P = 0.010). We observed no clear association for the other outcomes.'] Does a cumulative genetic risk score predict progression in Parkinson 's disease?