GBA1 and Parkinson disease: <h4>Introduction</h4>An association between severe <i>GBA1</i> variants and the progression of non-motor symptoms in PD has been reported, but the role of Parkinson's-risk (PD-risk) <i>GBA1</i> variants is less clear.<h4>Methods</h4>We assessed symptom progression in individuals with severe and PD-risk variants compared to non-carriers.