1. Department of Pediatric Neurology, National Neurosciences Institute, King Fahad Medical City, King Abdulaziz Bin Saud University, Riyadh, Saudi Arabia
2. Yorkshire Regional Genetics Service, DNA Laboratory, Ashley Wing, St James's University Hospital, United Kingdom
3. Medical Genetics Center and Genetics Unit, Department of Pediatrics, Ain Shams University, Cairo, Egypt
4. Department of Pediatrics, Ain Shams University, Cairo, Egypt