1. From the Wellcome Trust Centre for Human Genetics and Department of Clinical Neurology, University of Oxford; Oxford, United Kingdom (S-MO, APM, BMH, SVR, MRL, MJC, and GCE); Laboratory Medicine and Pathobiology Department, University of Toronto, Toronto, Canada (RV); and the 3Department of Medical Genetics and Faculty of Medicine, Division of Neurology, University of British Columbia, Vancouver,