[1] Catholic Univ, Paediat Neurol Unit, Rome, Italy
[2] Policlin Gemelli, Ctr Clin Nemo, Rome, Italy
[3] Univ Cent Florida, Coll Med, Nemours Childrens Hosp, Orlando, FL 32816 USA
[4] UCL Great Ormond St Inst Child Hlth, Dubowitz Neuromuscular Ctr, London, England
[5] Great Ormond St Hosp Sick Children, London, England
[6] Univ Cologne, Ctr Rare Dis, Ctr Mol Med, Inst Human Genet, Cologne, Germany
[7] Univ Cologne, Inst Genet, Cologne, Germany
[8] Columbia Univ, Med Ctr, Dept Rehabil & Regenerat Med, New York, NY USA
[9] Columbia Univ, Dept Neurol, Med Ctr, New York, NY USA
[10] Columbia Univ, Med Ctr, Dept Orthopaed Surg, New York, NY USA
[11] Harvard Med Sch, Childrens Hosp, Dept Orthopaed Surg, Boston, MA USA
[12] Hop Raymond Poincare, AP HP, Dept Pediat Intens Care Neurol & Rehabil, Unit Neuromuscular Disorders, Garches, France
[13] Univ Versailles St Quentin En Yvelines UVSQ, Hop Univ Paris Ile de France Ouest, INSERM, U1179, Paris, France
[14] Bambino Gesu Childrens Res Hosp, Dept Neurosci & Neurorehabil, Unit Neuromuscular & Neurodegenerat Disorders, Rome, Italy
[15] Univ Utah, Intermt Healthcare, Salt Lake City, UT USA
[16] Childrens Hosp Philadelphia, Div Pulmonol, Philadelphia, PA 19104 USA
[17] Royal Brompton & Harefield NHS Fdn Trust, NIHR Resp Biomed Res Unit, London, England
[18] Univ Wisconsin, Dept Pediat, Sch Med & Publ Hlth, Div Pediat Pulm,Amer Family Childrens Hosp, Madison, WI USA
[19] Harvard Med Sch, Boston Childrens Hosp, Dept Anesthesiol Perioperat & Pain Med, Div Crit Care, Boston, MA USA
[20] Univ Freiburg, Fac Med, Med Ctr, Dept Neuropediat & Muscle Disorders, Freiburg, Germany
[21] Univ Texas Southwestern Med Ctr Dallas, Div Pediat Neurol, Dept Pediat, Dallas, TX 75390 USA
[22] Univ Texas Southwestern Med Ctr Dallas, Div Pediat Neurol, Dept Neurol & Neurotherapeut, Dallas, TX 75390 USA
[23] Childrens Med Ctr, Dallas, TX 75235 USA
[24] Johns Hopkins Univ, Dept Neurol, Baltimore, MD 21218 USA
[25] Newcastle Univ, Policy Eth & Life Sci Res Ctr, Newcastle Upon Tyne, Tyne & Wear, England
[26] SMA Fdn, New York, NY USA
[27] Karolinska Inst, Dept Womens & Childrens Hlth, Paediat Neurol, Stockholm, Sweden