We previously reported on the epidemiology of GBA1 mutations in incident PD.1 Here we present long-term follow-up data of incident PD cases carrying pathogenic and ‘non-pathogenic’ variants in the GBA1 gene from two community-based cohorts: the ‘Cambridgeshire Incidence of Parkinson’s disease from General Practice to Neurologist’ (CamPaIGN) and ‘Parkinsonism: Incidence, Cognition and Non-motor heterogeneity in Cambridgeshire’ (PICNICS) cohorts. Here, GBA1 is linked to Parkinson disease.