Question

Christmas disease is another name of
A. Sleeping sickness
B. Down's syndrome
C. Haemophilia-B
D. Hepatitis

Answer 1

Christmas disease is caused due to deficiency of blood clotting factor or is caused by a mutation of the factor IX gene. It was named after Stephen Christmas as he was the first one to be encountered by this disease.

Complete step by step answer: Let’s us look at all the options to get the correct answer,
Option A, sleeping sickness: Sleeping sickness is another name for human African trypanosomiasis which is caused by an infectious parasite named Trypanosoma brucei , commonly called tsetse fly. Hence, this option is incorrect.
Option B, Down's syndrome: Down's syndrome is another name for trisomy 21 which is a genetic disorder which is caused due to abnormal cell division resulting in an extra copy of the 21st chromosome. Hence, the second option is also incorrect.
Option C, Haemophilia B: Christmas disease also known as Royal disease is another name for Hemophilia B which is caused due to deficiency of blood clotting factor IX. In this disease, blood cannot clot. Thus, this is the correct option.
Option D, Hepatitis: Hepatitis has 5 types and is caused due to swelling or inflammation of the liver. Hence, this is also an incorrect option.
So, the correct option is option C which is Haemophilia-B.

Note: There are three stages of hemophilia. They are as follows-
-Mild Haemophilia B which has factor levels about $6-30$ occurs in approx. $25$ of patients. It is seen they mostly have bleeding after a serious trauma or surgery, also they might suffer from menorrhagia or postpartum bleeding.
-Moderate Haemophilia B which has the factor levels of about $1-5$. Moderate hemophilia is seen in $15$ of patients. They have bleeding direct after injuries and spontaneous bleeding might be seen.
-Severe Haemophilia B is rarely seen and has factor levels of $<\text{ }1$. It is seen to occur in about $60$ of patients and has spontaneous bleeding very often into the muscles and joints.