In recent years, the increased recourse to GBA1 genotyping in PD3, the different response of patients carrying GBA1 variants (GBA1-PD) to advanced treatments for PD (i.e., deep brain stimulation-DBS)4, and the growing number of clinical trials testing GBA1-targeted therapies5, have created the need for standardized guidelines for genetic counselling, management and selection of patients for clinical trials1. The gene discussed is GBA1; the disease is Parkinson disease.