University of Oxford - Department of Clinical Neurosciences, Government of the United Kingdom - Manchester Centre for Clinical Neurosciences, UCL Institute of Neurology - Centre for Neuromuscular Disease, University College London - MRC Center for Neuromuscular Diseases, University of Oxford - Department of Clinical Neurosciences, University College London - MRC Center for Neuromuscular Diseases, University of Oxford - Nuffield Department of Clinical Neurosciences, National Hospital for Neurology and Neurosurgery, University of Oxford - Department of Clinical Neurosciences, University of Oxford - Department of Clinical Neurosciences and University College London - MRC Center for Neuromuscular Diseases