Question

Genetic disorder haemophilia is characterized by excessive loss of blood. Which of the following statements is not true in relation to this disorder?
A. It is lethal disease
B. Factor VIII or IX may be absent
C. It is X – linked disease
D. It is autosomal disease

Answer 1

Haemophilia is a genetic disorder in which the body is not able to form blood clots and does not stop the excessive flowing of blood. In addition, this is because the body lacks clotting proteins due to dysfunctioning in the cascade proteins.

Complete answer: Haemophilia is an inherited disease in which the body lacks production of blood clotting proteins and is not able to form a blood clot. Hence it leads to excessive flow of blood.
Haemophilia can be further classified into two types:
i) haemophilia A, in which the person lacks clotting factor VIII.
ii) haemophilia B, which is caused by low levels of clotting factor IX. It is an X – linked recessive disorder, in which the person inherits X Chromosome from one of its parents. Blood clotting factor VIII also called an antihemophilic factor is produced by liver cells which is essential for the coagulation of blood. Christmas Factor or factor IX belongs to the group of serine proteases of coagulation systems. The presence of two copies of abnormal genes in a person inherited from their parents leads to the development of traits or disease. Such disease inherited from their parents is called autosomal disease. So, haemophilia disease makes it clear that it is not an autosomal disease.
Hence option D is the right answer.

Note: The other types of haemophilia disease include haemophilia C, which is caused by low levels of factor XI, and low level of factor V causes parahemophilia. Acquired haemophilia can cause cancers, autoimmune disorders, and pregnancy. Diagnosis can be done by testing the blood for its ability to clot and its levels of clotting factors. Severe complications are seen in people with moderate and severe haemophilia. It includes deep internal bleeding, joint damage, transfusion-transmitted infection, adverse reactions, and intracranial haemorrhage. These complications occur from the disease itself or its treatment.