1 Department of Pediatrics, Division of Neurology, Children's Hospital of Philadelphia, United States; Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States.
2 College of Arts and Sciences, University of Pennsylvania, Philadelphia, PA 19104, United States.
3 Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States; Institució Catalana de Recerca i Estudis Avançats (ICREA), IDIBAPS, Hospital Clínic, Barcelona, Spain.
4 Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, United States. Electronic address: lynchd@mail.med.upenn.edu.