title: Reply.
authors.affiliation: Department of Pediatrics Seoul National University College of Medicine Seoul, Republic of Korea.
authors.forename: Seung Han
authors.initials: SH
authors.lastname: Shin
authors.affiliation: Department of Pediatrics Seoul National University College of Medicine Seoul, Republic of Korea; Department of Pediatrics Kangwon National University Hospital Chuncheon, Republic of Korea.
authors.forename: Sae Yun
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Pediatrics Seoul National University College of Medicine Seoul, Republic of Korea.
authors.forename: Han-Suk
authors.initials: HS
authors.lastname: Kim