1. Queen Square MRC Centre for Neuromuscular DiseasesInstitute of Neurology, University College London 8‐11 Queen Square, London WC1N 3BG United Kingdom
2. Clinical Outcomes Solutions Tucson Arizona USA
3. Department of NeurologyUniversity of Virginia Charlottesville Virginia USA
4. Neuromuscular Research DivisionUniversity of Kansas Fairway Kansas USA
5. Neurology DepartmentBrigham and Women's Hospital Boston Massachusetts USA