1. Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea.
2. Department of Pediatrics, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.
3. Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea.
4. Department of Laboratory Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.
5. School of Biosystem and Biomedical Science, Korea University College of Health Science, Seoul, Korea.
6. Department of Medical Statistics, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.