1. Department of Pediatrics, Eulji General Hospital, Seoul, Korea.
2. MG MED, Inc., Seoul, Korea.
3. Department of Medical Genetics, Ajou University Medical Center, Ajou University School of Medicine, Suwon, Korea.
4. Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.
5. Department of Physical Medicine and Rehabilitation, Ajou University Medical Center, Ajou University School of Medicine, Suwon, Korea.