Which of the following is an example of a hemolytic anemia?

Sickle cell anemia is classified as a hemolytic anemia due to its characteristic of red blood cells being prone to rupture or destruction. In sickle cell anemia, the hemoglobin within red blood cells is abnormal (hemoglobin S), causing these cells to assume a sickle shape, especially under low oxygen conditions. These misshapen cells are more fragile and can easily break apart, leading to a reduction in the overall number of red blood cells and resulting in anemia. Additionally, this hemolysis contributes to other complications, such as pain crises and an increased risk of infection.

In contrast, other types of anemia listed do not primarily result from the destruction of red blood cells. Aplastic anemia is a condition where the bone marrow fails to produce enough blood cells, iron-deficiency anemia is related to insufficient iron levels affecting hemoglobin production, and thalassemia involves genetic mutations that affect hemoglobin structure but are not primarily characterized by hemolysis to the same extent as sickle cell anemia. This underscores why sickle cell anemia is specifically categorized under hemolytic anemias.