Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, United States. Cairo University, Cairo, Egypt. Cairo University, Giza, Egypt. Ain Shams University, Cairo, Egypt. Zagazig University, Zagazig, Egypt. Assir Central Hospital, Abha, Saudi Arabia. University of Alabama Birmingham, Birmingham, Alabama, United States. Guy's and St Thomas' Hospital, London, Wyoming, United Kingdom. Hospital for Sick Children, Toronto, Canada. Cukurova University Medical Facility, Adana, Turkey. Chiesi Canada Corporation, Woodbridge, Canada. Chiesi Canada Corporation, Toronto, Canada.