An inborn error of metabolism that causes premature destruction of RBCs is?

NVS Staff Nurse - 2019

Pathology & Genetics

Easy

Appeared in: NVS Staff Nurse - 2019

Explanation

G6PD deficiency is the most common human enzymopathy, an inborn error of metabolism affecting the pentose phosphate pathway in red blood cells (RBCs).
The G6PD enzyme is critical for producing NADPH, which protects RBCs from oxidative damage.
A deficiency in G6PD leaves RBCs vulnerable to oxidative stress from certain drugs, infections, or fava beans, leading to hemolysis (premature destruction).
This process results in clinical features of acute hemolytic anemia, such as jaundice, dark urine, and fatigue.

Option A: Homocystinuria is an inherited disorder of amino acid metabolism (methionine), not RBC metabolism. Its primary complications are related to connective tissue and the vascular system, such as blood clots (thrombosis), lens dislocation, and skeletal abnormalities, not hemolysis.
Option C: Phenylketonuria (PKU) is an inborn error of phenylalanine metabolism. The buildup of phenylalanine is toxic to the central nervous system, causing severe intellectual disability and neurological problems if not treated with a special diet. It does not cause premature destruction of RBCs.
Option D: Celiac disease is an autoimmune disorder, not an inborn error of metabolism in the classic sense. It is triggered by the ingestion of gluten, leading to damage to the small intestine and malabsorption. While chronic disease can lead to anemia of chronic inflammation or iron deficiency anemia, it does not directly cause hemolytic anemia.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Inborn errors of metabolism and their hematological manifestations as background academic context rather than a clinical decision trigger.
Nurses must educate patients with G6PD deficiency to avoid known triggers, including fava beans and specific medications like sulfonamides, dapsone, and primaquine.
During a hemolytic crisis, nursing care focuses on monitoring vital signs, urine color (for hemoglobinuria), and signs of severe anemia (pallor, fatigue, tachycardia). Supportive care includes hydration and potentially blood transfusions.
Newborn screening for G6PD is crucial in many regions, as neonatal jaundice associated with G6PD can be severe and lead to kernicterus (brain damage) if not managed promptly with phototherapy or exchange transfusion.

How to Approach the Question

First, analyze the question to identify the key concepts: 'inborn error of metabolism' and 'premature destruction of RBCs' (which is the definition of hemolysis).
Next, evaluate each option based on its underlying pathology.
Recall or deduce that Homocystinuria and Phenylketonuria are disorders of amino acid metabolism with primary effects on the vascular/skeletal and nervous systems, respectively.
Recognize that Celiac disease is an autoimmune disorder affecting the gut, not a primary metabolic error causing hemolysis.
Identify G6PD deficiency as a classic example of an inherited enzyme defect (an inborn error of metabolism) that directly impacts the stability and survival of red blood cells, leading to hemolysis.

Concept Tested & Keywords

Concept Tested: Inborn errors of metabolism and their hematological manifestations.
Stem keywords: inborn error of metabolism, premature destruction of RBCs
Lead-in keywords: is

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