Received: 11 February 2020
Accepted: 14 February 2020
First Online: 4 May 2020
Ethics approval and consent to participate
: The study protocol was approved by the institution ethical review board (medical research ethics committee at National Research Centre, Cairo, Egypt) according to Helsinki Declaration 1975 revised in 2008.Comittee’s reference number is 1453. Written informed consent was obtained from all parents of both patients and control groups before getting them involved in the study. They were informed by the aim and potential benefits of the study.
: Not applicable.
: The authors declare that they have no competing interests.