Christmas disease is another name for :-
- Hepatitis B
- Sleeping sickness
- Haemophilia B
- Down's syndrome
Answer
(3) Haemophilia B
Solution
Haemophilia is a sex-linked recessive disease in which a protein involved in the cascade of blood clotting is affected.
⇒ Haemophilia A is due to deficiency of clotting factor VIII; haemophilia B is due to deficiency of clotting factor IX.
⇒ Haemophilia B was first described in a patient named Stephen Christmas, hence it is called Christmas disease.
Answer: (3)