Haemophilia is associated with?

Appeared in: AIIMS Patna NO - 2020

Explanation

Haemophilia is a well-known X-linked recessive disorder.
This means the genes responsible for producing clotting factors (Factor VIII for Haemophilia A and Factor IX for Haemophilia B) are located on the X chromosome.
Because males have only one X chromosome (XY), a single recessive gene on that chromosome will cause the disease.
Females (XX) are typically carriers as they have a second X chromosome with a normal gene, which is usually sufficient for normal clotting.

Option A: Chromosome 11 is not associated with haemophilia. It carries the gene for the beta-globin chain of haemoglobin.
Option B: The Y chromosome determines male sex but does not carry the genes for clotting factors VIII or IX.
Option C: Chromosome 21 is associated with Down syndrome, which is caused by having an extra copy of this chromosome (Trisomy 21).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain The genetic basis and chromosomal association of Haemophilia as background academic context rather than a clinical decision trigger.
Understanding the X-linked inheritance of haemophilia is crucial for patient and family education, particularly regarding genetic counseling.
Nurses must educate patients with haemophilia about the risk of bleeding and the importance of avoiding trauma and certain medications (like aspirin) that interfere with clotting.
A key nursing role is to support families in managing the condition, including administering factor replacement therapy and recognizing signs of bleeding episodes (e.g., joint pain and swelling).

How to Approach the Question

First, identify the core concept of the question, which is the genetic basis of 'Haemophilia'.
This is a factual recall question. Access your knowledge about common genetic disorders and their inheritance patterns.
Recall that haemophilia is a classic example of a sex-linked disorder.
Evaluate the options: 'Sex-linked' specifically refers to genes on the X or Y chromosomes. Haemophilia is specifically X-linked.
Eliminate the other options by recalling their associations: Chromosome 21 with Down syndrome and Chromosome 11 with sickle cell anemia.
Select 'X chromosome' as the correct answer based on this established medical fact.

Concept Tested & Keywords

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E6 PATHOLOGY QUICK REVIEWBased on Harsh Mohan Textbook of PATHOLOGY p. 133-135

E6 Medicine Davidson Principles Practice 24e p. 992-994

Practise the full AIIMS Patna NO - 2020

Attempt every question from this paper in a timed mock, then review the full solution for each one.