From the MRC Centre for Neuromuscular Diseases (T.D.G., S.R., S.S., M.G.H., D.M.K.), UCL Institute of Neurology, Queen Square, London; Fraser of Allander Neurosciences Unit (S.M.Z.), Royal Hospital for Sick Children, Yorkhill, Glasgow; and MRC Centre for Neuropsychiatric Genetics and Genomics (H.R.M.), Cardiff University School of Medicine, UK. (At 2010-07-27)