Accumulation of fructose-1-phosphate in the liver and kidney leads to:

• Inhibition of gluconeogenesis → severe hypoglycemia

• Inhibition of glycogen breakdown
• Hepatic and renal toxicity

Symptoms begin when the infant is exposed to fructose-containing foods (fruit juices, fruits, sweetened foods, sucrose-containing formulas).

• Vomiting after fructose ingestion
• Sweating, pallor, shakiness (hypoglycemia)
• Lethargy
• Jaundice
• Hepatomegaly
• Failure to thrive
• Aversion to sweet foods (natural protective behavior)

• Clinical suspicion based on symptoms after fructose exposure
• Genetic testing for ALDOB gene
• Elevated liver enzymes, low glucose during episodes Note: Fructose challenge test is avoided due to risk of severe reactions.

• Strict lifelong avoidance of fructose, sucrose, and sorbitol
• Diet must exclude: fruits, juices, table sugar, sweets, certain vegetables
• Use safe substitutes: glucose, maltodextrin-based products

Excellent when diagnosed early and diet strictly followed. Untreated disease leads to liver failure and renal damage.