Question

The absence of which of the following clotting factor leads to haemophilia A?

• A. Factor VII
• B. Factor VIII
• C. Factor IX
• D. Factor X

Answer 1

The correct option is B Factor VIII

Haemophilia is an inherited bleeding disorder characterized by lacking or low levels of clotting factors resulting in an inability or impaired ability of blood clotting. Hemophilia A is caused by a deficiency of clotting factor VIII. Option B is correct. Hemophilia B is also known as 'Christmas disease' and is caused by a deficiency of clotting factor IX. Factor VII is also called as proconvertin and its deficiency causes an autosomal recessive 'Alexander’s disease'. FVII is a protein that, when bound to tissue factor, initiates the clotting cascade, which leads to the formation of a blood clot. Factor X deficiency is known as Stuart-Prower factor deficiency and causes impaired blood clotting ability.

Thus, the correct answer is option B.