1 Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, U.S.A.
2 The Folkhälsan Institute of Genetics and the Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki, Finland.
3 Department of Pediatric Neurology, Centre for Neuromuscular Disorders in Children and Adolecents, University Hospital Essen, University of Duisburg-Essen, Germany.
4 Division of Child Neurology, Centre de Références des Maladies Neuromusculaires, Department of Pediatrics, University Hospital Liège & University of Liège, Liège, Belgium; MDUK Neuromuscular Centre, Department of Paediatrics, University of Oxford, Oxford, United Kingdom. Electronic address: Laurent.servais@paediatrics.ox.ac.uk.