1. Centre for Neuromuscular Diseases, Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology , London WC1N 3BG , UK
2. Waisman Center and Department of Comparative Biosciences, University of Wisconsin , Madison, WI 53706 , USA
3. Department of Clinical Neurophysiology, Norfolk and Norwich University Hospital , Norwich NR4 7UY , UK
4. Dubowitz Neuromuscular Centre, NIHR Biomedical Research Centre at UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital , London WC1N 1EH , UK