Received: 14 April 2020
Accepted: 3 July 2020
First Online: 23 July 2020
Ethics approval and consent to participate
: This study was approved by the ethical committee of Ain Shams University School of Medicine on the 10th of September 2017. All parents/guardians of the chosen subjects and controls provided informed written consent prior to participating in any study-related activities.
: Not applicable
: The authors declare that they have no competing interests.