Received: 1 April 2020
Accepted: 26 June 2020
First Online: 7 July 2020
Ethics approval and consent to participate
: The study protocol was approved by the Ethical Committee of Ain Shams University (no reference number was given), and written informed consent was obtained from all patients' parents to participate in the study.
: Written informed consent was obtained from all patients’ parents for publication of the study.
: The authors declare that they have no competing interests.