In hemophilia A disease bleeding occurs due to the deficiency of?

PGIMER Sangrur NO - 2023

Pathology & Genetics

Easy

Appeared in: PGIMER Sangrur NO - 2023

Explanation

Hemophilia A, also known as classic hemophilia, is a genetic bleeding disorder resulting from a deficiency or absence of clotting Factor VIII.
Factor VIII is a crucial protein that works with Factor IX in the intrinsic pathway of the coagulation cascade to activate Factor X, leading to the formation of a stable fibrin clot.
It is an X-linked recessive condition, meaning it predominantly affects males who inherit the faulty gene on the X chromosome from their mothers, while females are typically carriers.

Option A: Factor IV is the designation for calcium ions (Ca²+). While calcium is a necessary cofactor for several steps in the coagulation cascade, its deficiency is not the specific cause of Hemophilia A.
Option B: A deficiency in Factor VII causes a rare, autosomal recessive bleeding disorder (Factor VII deficiency), which affects the extrinsic pathway of coagulation. This is distinct from Hemophilia A.
Option D: A deficiency in Factor IX is the cause of Hemophilia B, also known as Christmas disease. Although its clinical presentation is nearly identical to Hemophilia A, it is a genetically distinct disorder.

Clinical Relevance

Nursing practice connection: Knowing Coagulation Disorders and Factor Deficiencies helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Accurate diagnosis of the specific factor deficiency (VIII vs. IX) is critical because treatment involves replacing the exact missing factor. Administering the wrong factor concentrate is ineffective.
Nurses play a key role in patient and family education regarding safety precautions (e.g., avoiding contact sports, using soft-bristled toothbrushes) and the early signs of bleeding to manage the condition effectively.
What if? If a patient presents with bleeding and a prolonged Activated Partial Thromboplastin Time (aPTT), but Factor VIII and IX levels are normal, the nurse should anticipate further testing for other intrinsic pathway defects (e.g., Factor XI for Hemophilia C) or von Willebrand disease.

How to Approach the Question

This is a factual recall question testing knowledge of specific hematological disorders.
First, identify the key disease mentioned in the question: 'Hemophilia A'.
Recall the different types of hemophilia and their corresponding factor deficiencies from your studies on coagulation disorders.
Specifically, differentiate Hemophilia A (Factor VIII deficiency) from the clinically similar Hemophilia B (Factor IX deficiency).
Evaluate the given options to find the one that correctly matches the deficiency for Hemophilia A.
Eliminate the other options by recalling their roles in coagulation or the different disorders they cause.

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