Fructose-1-phosphate aldolase deficiency, hereditary

Hereditary Fructose-1-phosphate Aldolase Deficiency
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Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Hypoglycemia, jaundice, vomiting, hepatomegaly
Complications	N/A
Onset	Infancy
Duration	Lifelong
Types	N/A
Causes	Genetic mutation in the Aldolase B gene
Risks	N/A
Diagnosis	Genetic testing, liver biopsy
Differential diagnosis	N/A
Prevention	N/A
Treatment	Dietary fructose restriction
Medication	N/A
Prognosis	Good with dietary management
Frequency	N/A
Deaths	N/A

Hereditary Fructose-1-phosphate Aldolase Deficiency, also known as Hereditary Fructose Intolerance (HFI), is a rare genetic disorder of carbohydrate metabolism caused by a deficiency of the enzyme Aldolase B. This enzyme is crucial for the proper metabolism of fructose, a sugar found in many foods. The deficiency leads to the accumulation of fructose-1-phosphate in the liver, kidneys, and small intestine, causing toxic effects and metabolic disturbances.

Pathophysiology

The condition is caused by mutations in the ALDOB gene, which encodes the enzyme Aldolase B. This enzyme is responsible for the cleavage of fructose-1-phosphate into dihydroxyacetone phosphate and glyceraldehyde, intermediates in the glycolytic pathway. In the absence of functional Aldolase B, fructose-1-phosphate accumulates, leading to a depletion of inorganic phosphate and ATP, and an increase in AMP, which is subsequently degraded to uric acid. This metabolic block results in severe hypoglycemia and other metabolic derangements.

Clinical Presentation

Symptoms of hereditary fructose-1-phosphate aldolase deficiency typically appear after the introduction of fructose-containing foods into the diet, such as fruits, certain vegetables, and sweeteners like sucrose and sorbitol. Common symptoms include:

• Severe hypoglycemia
• Jaundice
• Vomiting
• Abdominal pain
• Hepatomegaly (enlarged liver)
• Failure to thrive in infants

If left untreated, the condition can lead to liver and kidney damage, growth retardation, and even death.

Diagnosis

Diagnosis of hereditary fructose intolerance is based on clinical symptoms, dietary history, and confirmatory genetic testing. A liver biopsy may show characteristic histological changes, but genetic testing for mutations in the ALDOB gene is the definitive diagnostic method.

Management

The primary treatment for hereditary fructose-1-phosphate aldolase deficiency is the strict avoidance of dietary fructose, sucrose, and sorbitol. This involves careful dietary planning and education to avoid foods and medications containing these sugars. With proper dietary management, individuals with HFI can lead normal, healthy lives.

Prognosis

With early diagnosis and strict adherence to a fructose-free diet, the prognosis for individuals with hereditary fructose intolerance is excellent. Most patients can avoid the severe complications associated with the disorder by maintaining dietary restrictions.

Also see

• Fructose malabsorption
• Galactosemia
• Glycogen storage disease
• Metabolic disorder