Question

The incorrect statement in regard to Hemophilia is
A. It is an X-linked disease
B. It is a recessive disease
C. It is a dominant disease
D. A single protein involved in the clotting of blood is affected

Answer 1

Hint: Hemophilia is an inheritable disorder that is characterized by excessive uncontrollable bleeding at the site of cut or injury. The hemophilic person lacks the ability to clot the blood. Clotting is required to stop excessive bleeding in case of injury. The person carries a mutation on one of the chromosomes from a parent that causes the inability to produce clots.

Complete answer: Hemophilia is a recessive inheritable disease that leads to the inability to form clots. This condition is caused by the faulty gene associated with blood clotting factor formation. The gene lies in the X-chromosomes. It can be inherited even when a single X chromosome carrying the mutation is present. Thus, it is a recessive disorder as it does not need both the alleles to be mutated. A single mutated allele is enough to cause haemophilia. Thus, it is not a dominant disease. It is characterized by excessive bleeding without clot formation. Clotting is an essential process that is performed by clotting factors released by platelet cells. These factors or proteins are clotting factor XIII, clotting factor IX, and others. There are different types of haemophilia associated with a lack of different types of clotting factors. Hemophilia A is caused by a lack of clotting factor VIII and Hemophilia B is caused due to lack of clotting factor IX. But a similar characteristic is excessive bleeding. Bleeding can also be internal in joints or in the brain that can lead to seizures and death.
Therefore, the correct answer is option C.

Note: Hemophilia can be diagnosed early by blood clotting tests. A definite cure is not available as it is an inheritable disease but prevention is done. The preventive measures are avoiding cuts and minor injuries as much as possible. Clotting factors can be supplied to a haemophilia person if he/she gets cut or bleeding. Recombinant methods can also be used to make clotting factors.