Question

Which of the following is known as the Christmas factor?

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

Answer 1

The correct option is B Factor IX

Blood clotting is the process by which clots are formed at the surface of ruptured blood vessels to prevent the loss of blood from the body. A number of proteins are involved in the clotting process.
Haemophilia is a genetic disorder in which these clotting factors are either not produced or are produced in very small amounts which are not adequate for the clotting process to occur.

Haemophilia can be classified into 3 types based on the factor that is lacking for the clotting process.
I. Haemophilia A- caused due to lack of clotting factor VIII. Factor VIII is also known as anti-haemophilic globulin or anti-haemophilic factor.
II. Haemophilia B- caused due to lack of clotting factor IX. Factor IX is also known as the Christmas factor. Haemophilia B is also known as Christmas disease because it was first reported in 1952 in a 5 year old boy named Stephen Christmas.
III. Haemophilia C- caused due to lack of clotting factor XI. Factor XI is also known as plasma thromboplastin antecedent factor.
Clotting factor X is also known as Stuart-Prower factor but is not known to be associated with any form of haemophilia.