[1] UCL, Dept Cell & Dev Biol, London WC1E 6DE, England
[2] Francis Crick Inst, 1 Midland Rd, London NW1 1AT, England
[3] Kings Coll London, Randall Ctr Cell & Mol Biophys, London, England
[4] Sorbonne Univ, UMRS974, Ctr Res Myol, INSERM,Myol Inst AIM, Paris, France
[5] UCL Great Ormond St Inst Child Hlth, Dubowitz Neuromuscular Ctr, London, France
[6] Great Ormond St Hosp Sick Children, London, France