Affiliation: | 1. MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, London, WC1N 3BG, UK;2. Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, London, WC1N 3BG, UK;3. Medical Research Council Mammalian Genetics Unit, Harwell, Oxfordshire, OX11 0RD, UK;4. Department of Neurodegenerative Disease, UCL Institute of Neurology, London, WC1N 3BG, UK |