1. From the Washington University School of Medicine, St. Louis (T.M.M., R.C.B.); the Sean M. Healey and AMG Center for ALS, Massachusetts General Hospital, Harvard Medical School, Boston (M.E.C., S.B.), and Biogen, Cambridge (T.C., S. Chary, S. Chew, H.Z., F.W., I.N., D.G., P.S., L.F., T.A.F., S.F.) — both in Massachusetts; Montreal Neurological Institute and Hospital, Montreal (A.G.); the Sheffield Institute for Translational Neuroscience, University of Sheffield, and the National Institute for Health and...