A 6-month-old infant presents with hepatomegaly, doll-like face, lactic acidosis, and anemia. Liver biopsy reveals hepatocytes packed with glycogen and lipids, suggesting glucose-6-phosphatase deficiency. Which laboratory finding is most characteristic of this disorder?

1. A

   Fasting hypoglycemia

2. B

   Elevated cholesterol levels

3. C

   Low lactate concentration

4. D

   Reduced glutathione levels

Appeared in: INI-CET EXAM -2025

Explanation

• The question asks for the most characteristic finding of glucose-6-phosphatase deficiency (GSD Type Ia).
• The function of glucose-6-phosphatase is to release free glucose from the liver to maintain blood sugar levels.
• A deficiency in this enzyme directly blocks this final, critical step of both glycogenolysis and gluconeogenesis.
• Therefore, a profound and rapid drop in blood glucose during fasting (fasting hypoglycemia) is the most direct, immediate, and defining feature of the disease.

Why Other Options Were Wrong

• Option B: While elevated cholesterol (hyperlipidemia) is a common finding in GSD Type Ia, it is a secondary consequence of metabolic shunting. The primary, most direct, and life-threatening issue is the failure to maintain blood glucose.
• Option C: This is the opposite of what occurs. The stem itself mentions lactic acidosis. The metabolic block causes precursors to be shunted towards lactate production, leading to significantly elevated lactate levels.
• Option D: Reduced glutathione levels are associated with Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency, a completely different enzyme defect that affects the pentose phosphate pathway in red blood cells and leads to hemolytic anemia under oxidative stress.

Related Visual

• Visual 1: Flowchart - A metabolic pathway diagram showing gluconeogenesis and glycogenolysis, with a large red 'X' over the glucose-6-phosphatase step, illustrating how glucose-6-phosphate is trapped in the liver and cannot be released as glucose. Arrows should show the shunting of G6P to lactate and lipid synthesis pathways.
• Visual 2: Image - A clinical photograph of an infant with Von Gierke's disease, highlighting the characteristic 'doll-like' facies (chubby cheeks, thin extremities) and a protuberant abdomen due to massive hepatomegaly.

Clinical Relevance

• Nursing practice connection: Use the key finding related to Pathophysiology and key laboratory findings of Glycogen Storage Disease Type I (Von Gierke's Disease) to guide bedside assessment, documentation, and the next nursing action.
• Nursing management for infants with GSD Type Ia is centered on preventing hypoglycemia, which can cause seizures and irreversible brain damage.
• Key nursing interventions include administering frequent feeds (day and night) and uncooked cornstarch, which acts as a slow-release form of glucose.
• Nurses must educate the family on recognizing signs of hypoglycemia (irritability, lethargy, sweating) and the importance of strict dietary adherence.

How to Approach the Question

• Step 1: Identify the key clinical features in the stem: hepatomegaly, doll-like face, and lactic acidosis in an infant. Recognize this classic triad as pointing towards Glycogen Storage Disease Type Ia (Von Gierke's disease).
• Step 2: Recall the underlying enzyme defect in GSD Type Ia: glucose-6-phosphatase deficiency.
• Step 3: Understand the function of this enzyme: it's the final step to release free glucose from the liver.
• Step 4: Deduce the primary consequence of this enzyme block: the liver cannot release glucose, leading to severe hypoglycemia, especially during fasting.
• Step 5: Evaluate the options based on this primary consequence. Fasting hypoglycemia is the most direct result. The other metabolic derangements (high lactate, high lipids) are secondary effects.
• Step 6: Eliminate distractors. Low lactate is the opposite of what happens. Reduced glutathione relates to a different disease (G6PD deficiency).

Concept Tested & Keywords

• Concept Tested: Pathophysiology and key laboratory findings of Glycogen Storage Disease Type I (Von Gierke's Disease).
• Stem keywords: 6-month-old infant, hepatomegaly, doll-like face, lactic acidosis, glucose-6-phosphatase deficiency
• Lead-in keywords: most characteristic
• Clinical cues: The combination of hepatomegaly, doll-like facies, and lactic acidosis is a classic triad for GSD Type Ia.
• Clinical cues: Glucose-6-phosphatase deficiency directly points to a problem with glucose release from the liver.

Question ID

QTDaIIuZV--mhU_Yzj-LHd

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