[1] Univ Miami, Dept Human Genet, Hussman Inst Human Genom, Miami, FL USA
[2] Univ Tubingen, Dept Neurol, Tubingen, Germany
[3] C Besta Neurol Inst, Dept Clin Neurosci, Milan, Italy
[4] UCL Inst Neurol, MRC Ctr Neuromuscular Dis, London, England
[5] Univ Iowa, Dept Neurol, Iowa City, IA 52242 USA