Bettina Balint1,2, Enza Maria Valente3,4. 1. Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology Queen Square, London, UK. 2. Department of Neurology, University Hospital Heidelberg, Germany. 3. Department of Molecular Medicine, University of Pavia, Pavia, Italy. 4. Neurogenetics Unit, IRCCS Santa Lucia Foundation, Rome, Italy.