Sickle Cell Anemia

Overview


Plain-Language Overview

Sickle Cell Anemia is a genetic blood disorder that affects the red blood cells, which are responsible for carrying oxygen throughout the body. In this condition, the red blood cells become abnormally shaped like a crescent or sickle, which makes it harder for them to move through blood vessels. This can cause blockages that lead to pain episodes, organ damage, and increased risk of infections. The disease primarily affects the circulatory system and can cause symptoms such as fatigue, swelling, and delayed growth. It is inherited from parents who carry the mutated gene responsible for the abnormal hemoglobin. The sickled cells also break down more quickly, leading to anemia. Overall, this condition impacts oxygen delivery and causes chronic health problems.

Clinical Definition

Sickle Cell Anemia is a hereditary hemoglobinopathy characterized by the presence of abnormal hemoglobin S (HbS) due to a mutation in the HBB gene encoding the beta-globin chain. This mutation causes red blood cells to deform into a sickle shape under low oxygen conditions, leading to chronic hemolytic anemia and vaso-occlusion. The sickled erythrocytes have reduced deformability and increased adherence to vascular endothelium, resulting in microvascular obstruction and ischemic tissue injury. The disease manifests with recurrent pain crises, increased risk of infections due to functional asplenia, and end-organ damage including stroke and pulmonary complications. It is inherited in an autosomal recessive pattern, with homozygous individuals exhibiting the full clinical syndrome. The hallmark of the disease is the presence of HbS on hemoglobin electrophoresis and characteristic sickled cells on peripheral smear.

Clinical Presentation


Diagnostic Workup


Pathophysiology


Treatments


Prevention


Outcome & Complications


Differential Diagnoses


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