1. Asan Institute for Life Sciences, University of Ulsan College of Medicine, Seoul, Korea.
2. Department of Pediatrics, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea.
3. Department of Pediatrics, Chung-Ang University Hospital, Seoul, Korea.
4. Department of Pediatrics, The Catholic University of Korea, Daejeon St. Mary's Hospital, Daejeon, Korea.
5. Department of Pediatrics, Kyung Hee University Hospital at Gangdong, Seoul, Korea.
6. Department of Pediatrics, Chungnam National University Hospital, Daejeon, Korea.
7. Department of Pediatrics, Seoul National University Children's Hospital, Seoul, Korea.
8. Department of Pediatrics, University of Ulsan, Gangneung Asan Hospital, Gangneung, Korea.
9. Department of Pediatrics, Inje University Paik Hospital, Busan, Korea.
10. Department of Pediatrics, Pusan National University Hospital, Busan, Korea.
11. Department of Pediatrics and Adolescent Medicine, Myongji Hospital, Goyang, Korea.
12. Department of Pediatrics, Korea University Guro Hospital, Seoul, Korea.
13. Department of Pediatrics, Ewha Womans University Hospital, Seoul, Korea.
14. Department of Pediatrics, Korea University Ansan Hospital, Ansan, Korea.