Funding for this research was provided by:
National Natural Science Foundation of China (81300434)
Received: 13 September 2019
Accepted: 18 June 2020
First Online: 24 June 2020
Ethics approval and consent to participate
: This research was approved by the Beijing Children’s Hospital Institutional Ethics Committee. Informed consents were obtained from the parents or guardians of each patient according to the Declaration of Helsinki.
: All authors had full access to all of the data in the study and had final responsibility for the decision to submit for publication.
: The authors declare that they have no competing interests.