Sickle Cell Disease

Abstract

1. Timothy L. McCavit, MD* 1. *Division of Hematology-Oncology, Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX; Center for Cancer and Blood Disorders, Children's Medical Center Dallas, Dallas, TX. * Abbreviations: ACS: : acute chest syndrome Hgb: : hemoglobin HgbS: : sickle hemoglobin HSCT: : hematopoietic stem cell transplantation HU: : hydroxyurea IPD: : invasive pneumococcal disease PAH: : pulmonary artery hypertension PCV13: : pneumococcal conjugate vaccine PROPS: : Prophylactic Penicillin Study RBC: : red blood cell SCD: : sickle cell disease SS: : sickle cell anemia Sβ: : sickle β thalassemia TCD: : transcranial Doppler TRJV: : tricuspid regurgitant jet velocity VOC: : vaso-occlusive crises In the United States, sickle cell trait is carried by 7% to 8% of people of African ancestry, and the sickle hemoglobinopathies are estimated to affect 90,000 to 100,000 people. After completing this article, readers should be able to: 1. Understand how the sickle hemoglobin mutation leads to the various manifestations of sickle cell disease (SCD). 2. Identify common health maintenance needs for children with SCD. 3. Recognize the common acute complications of SCD and their treatment. 4. Assess the risks and benefits of the common treatment modalities for SCD. 5. Discuss the improved prognosis for children with SCD. The World Health Organization estimates that 7% of the world's population carries a hemoglobin (Hgb) mutation and that 300,000 to 500,000 children are born each year with severe hemoglobinopathy. The sickle Hgb (HgbS) mutation occurred independently at least four times (three times in sub-Saharan Africa and once in India or the Arabian peninsula) in regions with endemic malaria. In the heterozygous state, the sickle mutation provides protection against infection by the falciparum species of malaria and likely confers a survival advantage, leading to its continued high prevalence in some populations of sub-Saharan Africa and the Middle East/India. In the United States, sickle cell trait is carried by 7% to 8% of people of African ancestry, and the sickle hemoglobinopathies are estimated to affect 90,000 to 100,000 people. (1) US newborn screening data suggest that 1 in 2,500 newborns is affected by a form of sickle cell disease (SCD). SCD refers to a group of heterogeneous disorders that are unified by the presence of at least one β globin gene affected by the sickle mutation (position 6, β-globin gene; …