Which of the following is NOT a type of sickle cell disease?

• A. Sickle Cell anaemia
• B. Normal HbA
• C. Sickle cell trait
• D. HbSC

Answer: (B)

Sickle cell disease comes from having abnormal hemoglobins that cause red blood cells to sickle. The disease forms are tied to specific abnormal genotypes like HbSS (sickle cell anaemia) or HbSC disease, where abnormal hemoglobins are present in combinations that produce sickling. Normal HbA means the person has normal adult hemoglobin with no HbS or HbC, so there is no sickling tendency and no sickle cell disease. That’s why this option is not a disease type. (Sickle cell trait is a carrier state, not a disease in the same sense, but the question focuses on disease forms, so normal HbA clearly does not count as a disease type.)