1. MRC Prion Unit and Department of Neurodegenerative Disease, UCL Institute of Neurology
2. National Prion Clinic and National Hospital for Neurology & Neurosurgery, Queen Square, London, WC1N 3BG
3. Department of Medicine (Neuroscience), Monash University, Melbourne, Australia
4. Department of Neurology, University of California, San Francisco (UCSF), San Francisco, CA, USA
5. Department of Clinical Genetics, Churchill Hospital and Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, OX3 9DU, UK