1. Department of Human Genetics, Leiden University Medical Center , 2300 RC, Leiden , The Netherlands
2. Department of Pediatrics, University of Utah , Salt Lake City, UT 84112 , USA
3. Department of Neurology, University Hospital , 9000 Gent , Belgium
4. University Medical Center Utrecht , 3584 EA, Utrecht , The Netherlands
5. Department of Human Genetics, University of Utah , Salt Lake City, UT 84112 , USA
6. Neuromuscular Centre Nijmegen, Radboud University Nijmegen Medical Centre , 6525 GA, Nijmegen , The Netherlands
7. Department of Neurology, Algemeen Ziekenhuis Sint-Jan , 8000, Brugge , Belgium
8. Sorbonne Université, Inserm UMRS974, Institut de Myologie, Centre de Recherche en Myologie , F-75013 Paris , France
9. University of Kansas Medical Center , Kansas City, KS 66103 , USA
10. National Hospital For Neurology and Neurosurgery, UCL Queen Square Institute of Neurology , London, WC1N 3BG , UK
11. Department of Clinical Genetics, Leiden University Medical Center , 2300 RC, Leiden , The Netherlands
12. Unité de Morphologie Neuromusculaire, Institut de Myologie, AP-HP , F-75013, Paris , France
13. The John Walton Muscular Dystrophy Research Centre , Faculty of Medical Sciences, Newcastle upon Tyne, NE1 3BZ , UK
14. Department of Neurology, Saint-Luc UCL , 1200, Brussels , Belgium
15. Department of Neurology, University of Rochester Medical Center , NY 14642, Rochester , USA
16. Department of Neurology, University of Copenhagen , DK-2100 Copenhagen , Denmark