Funding for this research was provided by:
Korea Centers for Disease Control and Prevention (2018-ER6901-02)
Received: 17 August 2020
Accepted: 26 October 2020
First Online: 9 December 2020
Ethics approval and consent to participate
: The study protocol was in accordance with the tenets of Declaration of Helsinki and was approved by the Institutional Review Board of Seoul National University.
: Three families agreed to report the case with patients’ video clips. Independent written informed consents were obtained from the parents. We greatly appreciate the patients and their families for providing their videos and agreeing to this study.
: The authors have no conflict of interest or financial relationship to disclose.