[1] Univ Manchester, Ctr Musculoskeletal Res, Manchester, Lancs, England
[2] Salford Royal NHS Fdn Trust, Salford, Lancs, England
[3] Radboud Univ Nijmegen, Med Ctr, Ctr Neurosci Donders, Dept Neurol,Inst Brain Cognit & Behav, Nijmegen, Netherlands
[4] Leiden Univ, Dept Neurol, Med Ctr, Leiden, Netherlands
[5] La Pitie Salpetriere Hosp, Dept Internal Med, Paris, France
[6] Karolinska Inst, Karolinska Univ Hosp, Rheumatol Unit, Dept Med, Stockholm, Sweden
[7] UCL, MRC Ctr Neuromuscular Dis, London, England
[8] Radboud Univ Nijmegen, Radboud Inst Mol Life Sci, Dept Biomol Chem, Nijmegen, Netherlands
[9] Radboud Univ Nijmegen, Inst Mol & Mat, Nijmegen, Netherlands
[10] Oxford Univ Hosp, Nuffield Dept Clin Neurosci, Oxford, England
[11] Univ Manchester, Ctr Integrated Genom Med Res, Manchester, Lancs, England
[12] Walton Ctr Neurol & Neurosurg, Liverpool, Merseyside, England
[13] Newcastle Upon Tyne Hosp NHS Fdn Trust, Newcastle Upon Tyne, Tyne & Wear, England
[14] Nice Univ Hosp, Peripheral Nervous Syst Muscle & ALS Dept, Nice, France
[15] Univ Liverpool, MRC ARUK Inst Ageing & Chron Dis, Liverpool, Merseyside, England