1. From the Nord/Est/Ile-de-France Neuromuscular Reference Center (G.F.-E., G.Q., M. Masingue, S.L.-L., A.B., T.S.), Institut de Myologie, Pitié-Salpêtrière Hospital, Paris; Electromyography and Neuromuscular Department (J.T., A.P., F.B.), Hospices Civils de Lyon; Centre for Neuromuscular Diseases (C.J.R., M.M.R.), UCL Queen Square Institute of Neurology, London, United Kingdom; Neurology Department (N.L.F.), Pitié-Salpêtrière Hospital, Paris; Nord/Est/Ile-de-France Neuromuscular Reference Center (M....