Pediatric Movement Disorders Program (S.A.L., S.B., J.H., J.L., S.R.P.-L., M.C.K.), Barrow Neurological Institute, Phoenix Children's Hospital; Departments of Child Health, Neurology, Genetics and Cellular & Molecular Medicine (S.A.L., S.B., J.L., S.R.P.-L., M.C.K.), University of Arizona College of Medicine; Division of Neuroradiology (P.C.), Department of Radiology, Phoenix Children's Hospital, AZ; Programs in Neuroscience and Molecular & Cellular Biology (A.H., A.M.), Arizona State University, Tempe; and Department of Genetics (S.C.J.), Washington University, St. Louis, MO; Department of Genetics (K.B.), Yale University, New Haven, CT.