Which disease involves abnormally shaped red blood cells, crescent-shaped, causing anemia and potential organ damage, inherited with two genes needed for expression?

Which disease involves abnormally shaped red blood cells, crescent-shaped, causing anemia and potential organ damage, inherited with two genes needed for expression?

• A. Sickle cell anemia
• B. Hypothermia
• C. Myocardial infarction
• D. Congestive heart failure

Answer: (A)

This question tests understanding of a hereditary red blood cell disorder where cells become crescent-shaped, leading to anemia and potential organ damage, and requires two copies of the mutated gene to express the disease. Red blood cells with abnormal hemoglobin S polymerize when oxygen levels drop, becoming rigid and sickle-shaped. These misshapen cells have a shorter lifespan, causing chronic hemolytic anemia, and their rigidity can block small vessels, leading to painful episodes and ischemic injury in organs. The pattern of inheritance is autosomal recessive, so full disease usually appears only when a person inherits two mutated beta-globin genes; carriers with one mutated gene typically have little to no symptoms. The other conditions listed do not fit a hereditary, crescent-shaped red blood cell disorder and do not require two mutated genes for expression. The described condition is sickle cell anemia.