[1] UCL Great Ormond St Inst Child Hlth, Dubowitz Neuromuscular Ctr, 30 Guildford St, London WC1N 1EH, England
[2] UCL, Natl Inst Hlth Res, Great Ormond St Inst Child Hlth, Biomed Res Ctr, London WC1N 1EH, England
[3] Newcastle Univ, John Walton Muscular Dystrophy Res Ctr, MRC Ctr Neuromuscular Dis, Inst Genet Med, Newcastle Upon Tyne, Tyne & Wear, England
[4] Hop Armand Trousseau, Inst I Mot, Paris, France
[5] CHU Liege, Ctr Reference Malad Neuromusculaires, Liege, Belgium
[6] Radboud Univ Nijmegen, Amalia Childrens Hosp, Dept Rehabil, Med Ctr, Nijmegen, Netherlands
[7] Leiden Univ, Dept Neurol, Med Ctr, Leiden, Netherlands
[8] Duchenne Ctr Netherlands, Leiden, Netherlands
[9] Newcastle Upon Tyne Hosp NHS Fdn Trust, Int Ctr Life, Inst Human Genet, Northern Genet Serv, Cent Pkwy, Newcastle Upon Tyne, Tyne & Wear, England