What characterizes sickle cell anemia?

Sickle cell anemia is characterized by a change in the shape of erythrocytes, or red blood cells. In this condition, the normal biconcave disc shape of red blood cells is altered into a crescent or sickle shape due to a mutation in the hemoglobin gene. This structural change occurs because of the presence of abnormal hemoglobin called hemoglobin S (HbS). When deoxygenated, HbS causes the red blood cells to become rigid and take on a sickle shape.

This altered shape is significant because it leads to various complications. Sickle-shaped cells can get lodged in small blood vessels, impeding blood flow and causing pain, anemia, and increased risk for infections. The reduced flexibility of these cells also means they are more prone to rupture, leading to a lower overall count of functional red blood cells and contributing to anemia. Therefore, the characteristic deformity of the cells not only defines the disease but also directly impacts the clinical manifestations of sickle cell anemia.