Question

Which of the following is called christmas disease?

• A. Haemophilia A
• B. Haemophilia B
• C. Colour blindness
• D. Down's syndrome

Answer 1

Answer: (B)

Haemophilia B

Haemophilia B is a blood clotting disorder caused by a mutation of the factor IX gene, leading to a deficiency of factor IX. It is the second most common form of haemophilia, rarer than haemophilia A. It is also called Christmas disease, named after Stephen Christmas, the first patient described with this disease.

Therefore, the correct answer is option B.