Received: 28 November 2016
Accepted: 19 February 2018
First Online: 8 March 2018
Ethics approval and consent to participate
: This study was conducted after obtaining appropriate written informed consent from the parents of all participants, and the Institutional Review Board (IRB) at Asan Medical Center approved this study (IRB number: 2016–1098).
: A written informed consent for publication was obtained from each patient or responsible family member.
: No potential conflict of interest relevant to this article was reported.
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