1. Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Korea.
2. Department of Pediatrics, Kyung Hee University Medical Center, Kyung Hee University College of Medicine, Seoul, Korea.
3. Department of Pediatrics, Inje University Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea.
4. Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea.
5. Department of Pediatrics, Dong-A University Hospital, Dong-A University College of Medicine, Busan, Korea.
6. Department of Pediatrics, Chosun University Hospital, Chosun University College of Medicine, Gwangju, Korea.
7. Department of Pediatrics, Dankook University Hospital, Dankook University College of Medicine, Cheonan, Korea.
8. Department of Pediatrics, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.