Sickle cell anemia is primarily characterized by what?

• A. Inherited blood disorder with crescent-shaped red blood cells due to defective hemoglobin
• B. Acute viral infection
• C. Nutritional deficiency
• D. Autoimmune reaction

Answer: (A)

Sickle cell anemia is a genetic disorder of red blood cells caused by a mutation in the beta-globin gene that makes abnormal hemoglobin, called hemoglobin S. When oxygen levels drop, this hemoglobin tends to polymerize, causing red blood cells to deform into a crescent or sickle shape. These stiff, fragile cells don’t flow as well, so they break down faster (hemolytic anemia) and can clog small blood vessels, leading to pain crises and potential organ damage. Because it’s inherited, people with two defective genes typically have the disease, while those with one copy are usually carriers. This is why the best description is an inherited blood disorder with crescent-shaped red blood cells due to defective hemoglobin. The other options describe conditions that aren’t defined by this genetic hemoglobin change or by crescent-shaped red cells.