Question

Deficiency of the blood clotting factor VIII results in:

• A. Haemophilia-A
• B. Haemophilia-B
• C. Christmas disease
• D. Sickle cell anemia

Hint:

Remember: Factor VIII $\rightarrow$ Haemophilia-A, whereas Factor IX $\rightarrow$ Haemophilia-B (Christmas disease).

Answer 1

The Correct Option is A

Concept: Blood clotting is a complex physiological process involving several clotting factors. Any deficiency in these factors leads to bleeding disorders. Factor VIII and Factor IX are the most commonly affected clotting factors in inherited haemophilia.

Step 1: Understanding the role of Factor VIII.
Factor VIII is an essential clotting factor that participates in the intrinsic pathway of blood coagulation. It helps in the formation of a stable blood clot after injury.

Step 2: Effect of deficiency of Factor VIII.
When Factor VIII is deficient or absent, blood clotting becomes very slow. As a result, affected individuals experience prolonged bleeding even after minor injuries. This condition is known as Haemophilia-A.

Step 3: Eliminating incorrect options.

• Haemophilia-B occurs due to deficiency of Factor IX.
• Christmas disease is another name for Haemophilia-B.
• Sickle cell anemia is caused by mutation in the beta-globin gene and is unrelated to clotting factors. Therefore, deficiency of Factor VIII causes Haemophilia-A.