Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA, USA.Reata Pharmaceuticals, Dallas, TX, USA.Victorian Clinical Genetics Services, Murdoch Children's Research Institute, Parkville, Victoria, Australia.Department of Neurology, McKnight Brain Institute, University of Florida Health System, Gainesville, FL, USA.Department of Pediatrics, University of Florida Health System, Gainesville, FL, USA.Department of Neurology, Ohio State University College of Medicine, Columbus, OH, USA.Department of Neurology, Medical University Innsbruck, Innsbruck, Austria.Department of Neurology, Medical University Innsbruck, Innsbruck, Austria.Istituto di Ricovero e Cura a Carattere Scientifico-Carlo Besta Neurological Institute, Milan, Italy.Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, IA, USA.University College London Hospital, London, United Kingdom.Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.Department of Neurology, University of South Florida Ataxia Research Center, Tampa, FL, USA.Department of Neurology, University of California, Los Angeles, Los Angeles, CA, USA.Reata Pharmaceuticals, Dallas, TX, USA.Reata Pharmaceuticals, Dallas, TX, USA.Reata Pharmaceuticals, Dallas, TX, USA.