Importance Parkinson disease (PD) is heterogeneous in symptom manifestation and rate of
progression. Identifying factors that influence disease progression could provide
mechanistic insight, improve prognostic accuracy, and elucidate novel therapeutic targets.
Objective To determine whetherGBAmutations and the E326K polymorphism modify PD
symptom progression. Design, Setting, and Participants The entireGBAcoding region was
screened for mutations and E326K in 740 patients with PD enrolled at 7 sites from the PD …