Susceptibility single-nucleotide polymorphisms (SNPs) for Parkinson disease (PD) combined with a cumulative polygenic risk score (PRS) were associated with faster motor and cognitive decline in patients, according to a recent study. Thus, these genetic markers may be associated with not only PD susceptibility but also disease progression in multiple domains. This longitudinal, population-based, cohort study of 285 patients of European ancestry with incident PD genotyped 23 genome-wide association study SNPs. 199 patients were followed up for a mean (SD) of 5.3 (2.1) years for progression; 57 patients had died or were too ill for follow-up, and 29 withdrew or could not be contacted. Of total patients undergoing genotyping, 160 were men (56.1%) and 125 were women (43.9%); the mean (SD) age at diagnosis was 69.1 (10.4) years. Researchers found:

• The weighted PRS was associated with significantly faster cognitive decline, measured by change in the Mini-Mental State Examination (hazard ratio [HR] per 1 SD, 1.44).
• The PRS was also associated with faster motor decline, measured by time to Hoehn & Yahr Scale stage 3 (HR, 1.34) and change in Unified Parkinson’s Disease Rating Scale part III score (HR, 1.42).