Competing interests: Michael Schlossmacher reports receiving research funding from the Canadian Institutes of Health Research (CIHR), Michael J. Fox Foundation, Weston Brain Institute, Ontario Brain Institute, Parkinson Canada, Parkinson Research Consortium Ottawa, Department of Medicine (The Ottawa Hospital) and the Uttra and Sam Bhargava Family to conduct research into the pathogenesis of Parkinson disease and to model its variants. Dr. Schlossmacher is co-inventor of several patents to explore potential therapeutics based on the link between the GBA1 gene and synucleinopathy disorders, which have been licensed to Genzyme-Sanofi. All funding was outside the current work. David Grimes reports receiving personal fees from the Department of Justice (Government of Canada), from Allergan and from Ipsen, outside the submitted work. Suneil Kalia reports receiving grants from CIHR and the Michael J. Fox Foundation, as well as an honorarium (speaker fee) from Medtronic, outside the submitted work. Kerrie Schoffer reports receiving a funding grant from Medtronic to attend a deep brain stimulation course. Anne-Louise Lafontaine reports receiving personal fees from AbbVie (advisory board), during the conduct of the study. Janis Miyasaki reports receiving grants from the Patient Centered Outcomes Research Institute and from Merz, and royalties from UpToDate, outside the submitted work. Alexander Rajput reports receiving personal fees from Teva and Ipsen, outside the submitted work. Susan Fox reports receiving consultancy fees from Sunovion and Paladian, speaker honoraria from Teva and Zambon, and advisory board fees from Acadia, outside the submitted work. Brian Hutton reports receiving honoraria from the Cornerstone Research Group, outside the submitted work. Ronald Postuma reports receiving grants and personal fees from Fonds de la Recherche en Santé; grants from CIHR, Parkinson Canada, the W. Garfield Weston Foundation, the Michael J. Fox Foundation and the R. Howard Webster Foundation; personal fees from Takeda, Roche and Prothena, Teva Neuroscience, Novartis Canada, Biogen, Boehringer Ingelheim, Theranexus, GE Healthcare, Jazz Pharmaceuticals, AbbVie, Janssen, Otsuka Pharmaceutical, PhotoPharmics and Inception Sciences, all outside the submitted work. Dr. Postuma also reports being the Chair of the Scientific Advisory Board of Parkinson Canada, outside the submitted work. Tiago Mestre reports receiving personal fees from AbbVie and Medtronic, during the conduct of the study. Olga Suchowersky reports receiving personal fees from Sunovion, and grants from AbbVie, Apopharma and Biotie, during the conduct of the study. Dr. Suchowersky also reports receiving a grant from Teva outside the submitted work. No other competing interests were declared.