Which statement is true regarding hemophilia?
A.
Hemophilia is not hereditary in nature.
B.
Hemophilia can be treated by replacement therapy.
C.
Hemophilia is an X-linked dominant genetic disorder.
D.
Hemophilia B is the most common form of hemophilia.
The correct answer and Explanation is :
The correct answer is B. Hemophilia can be treated by replacement therapy.
Explanation:
Hemophilia is a hereditary blood disorder characterized by the inability to form blood clots properly, leading to prolonged bleeding. This condition is caused by a deficiency or absence of clotting factors, which are proteins in the blood that control bleeding.
- Hemophilia is hereditary (eliminating option A). Hemophilia is primarily an X-linked recessive genetic disorder, meaning the defective gene is located on the X chromosome. It primarily affects males because they have only one X chromosome. Females, having two X chromosomes, are typically carriers unless both X chromosomes are affected, which is rare.
- Hemophilia is not X-linked dominant (eliminating option C). Since it is recessive, females are usually carriers unless both of their X chromosomes are affected, while males who inherit the defective gene from their carrier mothers will show symptoms of the disease.
- There are two main types of hemophilia:
- Hemophilia A: Caused by a deficiency of clotting factor VIII.
- Hemophilia B: Caused by a deficiency of clotting factor IX. Hemophilia A is the more common form, affecting approximately 80% of hemophiliacs, while Hemophilia B is less common, affecting around 20% of those with hemophilia (eliminating option D).
- Replacement therapy, which involves injecting the missing clotting factors (either factor VIII for Hemophilia A or factor IX for Hemophilia B), is the primary treatment for managing hemophilia (making option B correct). This therapy helps prevent or control bleeding episodes, particularly after injuries or surgeries. It is usually administered on demand but can also be given prophylactically to prevent spontaneous bleeding in severe cases.
Though there is no cure for hemophilia, replacement therapy significantly improves the quality of life for individuals with the condition.