1. From the Institute of Myology, Neuromuscular Investigation Center, NMR Laboratory, Bâtiment Babinski, Groupe Hospitalier Pitié-Salpêtrière, 47-83 boulevard Vincent Auriol, 75651 Paris Cedex 13, France (B.M., P.Y.B., E.C.d.A.A., Y.F., H.R.); and Institute of Myology, Reference Center for Muscle Diseases Paris-Est, Paris, France (K.W.).