1. Department of Pediatrics, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
2. Department of Pediatrics, Dankook University Hospital, Cheonan, Korea.
3. Department of Pediatrics, Pediatric Clinical Neuroscience Center, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Korea.
4. Department of Pediatrics, Seoul National University Bundang Hospital, Seoul, Korea.
5. Department of Biostatistics, SMG-SNU Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
6. Department of Microbiology, Brain Korea 21 Plus Project for Medical Science, Severance Biomedical Science Institute and Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul, Korea.