RT Book, Section A1 Marshall, John P. A2 Tintinalli, Judith E. A2 Ma, O. John A2 Yealy, Donald M. A2 Meckler, Garth D. A2 Stapczynski, J. Stephan A2 Cline, David M. A2 Thomas, Stephen H. SR Print(0) ID 1166596080 T1 Sickle Cell Disease in Children T2 Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 9e YR 2020 FD 2020 PB McGraw-Hill Education PP New York, NY SN 9781260019933 LK accessmedicine.mhmedical.com/content.aspx?aid=1166596080 RD 2024/03/28 AB Sickle cell disease is a spectrum of blood disorders of which sickle cell anemia (SCA) is the most serious. SCA is found primarily in children of African, Arab, or Mediterranean descent. It is caused by a single amino acid substitution in the sixth position of the β-globulin chain of normal adult hemoglobin (HbA), which creates the abnormal sickle hemoglobin (HbS). The HbS chain found in patients with SCA creates a hydrophobic region of the hemoglobin tetramer when it is deoxygenated.1 In this state, noncovalent polymerization of the hemoglobin molecules creates chains that distort the shape of the membrane, causing the characteristic sickle appearance. The altered red blood cell shape and its associated rigidity and decreased deformability cause sickle cells to impede blood flow. This process is primarily responsible for the clinical manifestations of SCA through two mechanisms: hemolytic anemia and vaso-occlusion with subsequent ischemia-reperfusion injury. Interruption of blood flow created by the abnormal cells leads to poor tissue perfusion, acidosis, and hypoxia, which cause further sickling. The need to reverse these conditions is central to the management of SCA-related complications.