## **Core Concept**
The child's symptoms suggest a disorder of carbohydrate metabolism, specifically a condition that affects the body's ability to properly utilize glucose. The symptoms of hepatomegaly, recurrent episodes of vomiting, jaundice, and hypoglycemia, along with an aversion to sweet foods, point towards a condition known as Hereditary Fructose Intolerance (HFI).

## **Why the Correct Answer is Right**
The correct answer, **Fructose-1-phosphate aldolase (Aldolase B)**, is deficient in Hereditary Fructose Intolerance. This enzyme is crucial for the metabolism of fructose, a sugar found in many fruits, vegetables, and as a component of sucrose (table sugar). When fructose is ingested, it is first converted into fructose-1-phosphate by the enzyme fructokinase. Aldolase B then splits fructose-1-phosphate into glyceraldehyde and dihydroxyacetone phosphate, which can then enter glycolysis to produce energy or be used in gluconeogenesis. A deficiency in aldolase B leads to the accumulation of toxic metabolites when fructose is consumed, causing the symptoms observed in the child.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Glucose-6-phosphatase deficiency leads to von Gierke's disease, a condition characterized by severe hypoglycemia, lactic acidosis, and hepatomegaly due to an inability to convert glucose-6-phosphate to glucose for release into the bloodstream. While it causes hypoglycemia and hepatomegaly, the aversion to sweet foods and specific episodes related to fructose intake are not characteristic.
- **Option B:** This option seems to refer to a deficiency in another enzyme but is not clearly specified. However, based on the context, it's unlikely to directly relate to the symptoms described for Hereditary Fructose Intolerance.
- **Option D:** This option does not directly correspond with a well-known enzyme deficiency related to the symptoms described.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl for Hereditary Fructose Intolerance is that affected individuals often develop an aversion to sweet foods (or fruits and vegetables) due to the severe symptoms that occur after ingestion of fructose-containing foods. This condition is distinct from other metabolic disorders like lactose intolerance or glucose-galactose malabsorption, which have different triggers and mechanisms.

## **Correct Answer:** . Fructose-1-phosphate aldolase (Aldolase B)