1 Powell Gene Therapy Center and Child Health Research Institute, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA. Electronic address: barry.byrne@ufl.edu.
2 Powell Gene Therapy Center and Child Health Research Institute, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL, USA.
3 Dubowitz Neuromuscular Centre, University College London, Great Ormond Street Institute of Child Health, London, UK; National Institute for Health Research Great Ormond Street Hospital Biomedical Research Centre, London, UK.