1. Department of Haematology and Blood Transfusion, College of Medicine, University of Lagos, Lagos, Nigeria;
2. Department of Haematology and Blood Transfusion, Lagos University Teaching Hospital, Id-Aarba, Lagos, Nigeria;
3. Department of Paediatrics, Lagos State College of Medicine, Ikeja, Lagos, Nigeria;
4. DNA Laboratory, Sickle Cell Foundation Nigeria, Lagos, Nigeria;
5. Department of Paediatrics, Faculty of Medicine, Kuwait University, Kuwait City, Kuwait