Funding for this research was provided by:
JSPS KAKENHI (JP20K16875)
Received: 15 December 2020
Accepted: 19 April 2021
First Online: 7 May 2021
: The study was approved by the Ethics Committee on Human Research at Tokyo Metropolitan Children’s Medical Center (Approval 2020b-94). All procedures performed in the study were in accordance with national ethical guidelines for medical and health research involving human subjects and with the 1964 Helsinki declaration as well as its later amendments. Due to the retrospective nature of this study the need for informed consent was waived by the Ethics Committee on Human Research at Tokyo Metropolitan Children’s Medical Center.
: Not applicable.
: The authors declare that they have no competing interests.