Author information:
(1)Medical Research Council (MRC) Centre for Neuromuscular Diseases, University 
College London (UCL) Institute of Neurology, Queen Square, London WC1N 3BG, UK. 
Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of 
Neurology, Queen Square, London WC1N 3BG, UK.
(2)Medical Research Council (MRC) Centre for Neuromuscular Diseases, University 
College London (UCL) Institute of Neurology, Queen Square, London WC1N 3BG, UK.
(3)Department of Neurology, University of Kansas Medical Center, 3901 Rainbow 
Boulevard, Mail Stop 2012, Kansas City, KS 66160, USA.
(4)Department of Biostatistics, University of Kansas Medical Center, Kansas 
City, KS 66160, USA.
(5)Department of Health, Sport, and Exercise Science, The University of Kansas, 
Lawrence, KS 66045-7567, USA.
(6)Victor Horsley Department of Neurosurgery, National Hospital for Neurology 
and Neurosurgery, UCL Hospitals, Queen Square, London WC1N 3BG, UK.
(7)The Francis Crick Institute, Lincoln's Inn Fields Laboratory, 44 Lincoln's 
Inn Fields, London WC2A 3LY, UK.
(8)Department of Cell & Molecular Biology, St. Jude Children's Research 
Hospital, Memphis, TN 38105-3678, USA.
(9)Department of Neurology, University of Kansas Medical Center, 3901 Rainbow 
Boulevard, Mail Stop 2012, Kansas City, KS 66160, USA. l.greensmith@ucl.ac.uk 
mdimachkie@kumc.edu.
(10)Medical Research Council (MRC) Centre for Neuromuscular Diseases, University 
College London (UCL) Institute of Neurology, Queen Square, London WC1N 3BG, UK. 
Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of 
Neurology, Queen Square, London WC1N 3BG, UK. l.greensmith@ucl.ac.uk 
mdimachkie@kumc.edu.