1 Unit of Medical Genetics and Neurogenetics, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Istituto Neurologico Carlo Besta, Milan, Italy.
2 Wellcome Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.
3 National Institute for Health Research Oxford Biomedical Research Centre, Oxford, United Kingdom.
4 Centre de Référence des Maladies Neuromusculaires, Centre Hospitalier Universitaire d'Angers, Angers, France.
5 Department of Genetics, Yale School of Medicine, New Haven, CT, United States.