What is the most common type of hemophilia?

What is the most common type of hemophilia?

• A. Hemophilia A
• B. Hemophilia B
• C. Hemophilia C
• D. Hemophilia D

Answer: (A)

The most common type is due to a deficiency of factor VIII, which disrupts the intrinsic pathway of coagulation. This form is inherited in an X-linked recessive pattern, so it mainly affects males, while female carriers can pass it on and occasionally have mild symptoms. Hemophilia A accounts for the majority of hemophilia cases—roughly four out of five—making it the most frequent form. The other types are much rarer: deficiency of factor IX (a different, less common bleeding disorder) is less common than A, factor XI deficiency (hemophilia C) is rare and usually autosomal recessive, and the so-called Hemophilia D is exceedingly uncommon. Because factor VIII is essential for proper thrombin generation in the intrinsic pathway, its absence leads to a tendency for mucocutaneous and deep tissue bleeding, including joint bleeds. Diagnostically, you’d see a prolonged aPTT with a normal PT, and the specific deficiency is confirmed by low factor VIII activity. Treatments include desmopressin to raise endogenous factor VIII stores for milder cases, or replacement therapy with factor VIII concentrates for more severe disease.

The most common type is due to a deficiency of factor VIII, which disrupts the intrinsic pathway of coagulation. This form is inherited in an X-linked recessive pattern, so it mainly affects males, while female carriers can pass it on and occasionally have mild symptoms. Hemophilia A accounts for the majority of hemophilia cases—roughly four out of five—making it the most frequent form. The other types are much rarer: deficiency of factor IX (a different, less common bleeding disorder) is less common than A, factor XI deficiency (hemophilia C) is rare and usually autosomal recessive, and the so-called Hemophilia D is exceedingly uncommon. Because factor VIII is essential for proper thrombin generation in the intrinsic pathway, its absence leads to a tendency for mucocutaneous and deep tissue bleeding, including joint bleeds. Diagnostically, you’d see a prolonged aPTT with a normal PT, and the specific deficiency is confirmed by low factor VIII activity. Treatments include desmopressin to raise endogenous factor VIII stores for milder cases, or replacement therapy with factor VIII concentrates for more severe disease.