Fructose-1-phosphate aldolase deficiency, heredita

Fructose-1-phosphate Aldolase Deficiency, Hereditary

Fructose-1-phosphate aldolase deficiency, also known as hereditary fructose intolerance (HFI), is a rare genetic disorder that affects the metabolism of fructose, a type of sugar found in many foods. This condition is caused by a deficiency of the enzyme aldolase B, which is necessary for the proper breakdown of fructose in the liver, kidney, and intestine.

Pathophysiology

In individuals with hereditary fructose intolerance, the deficiency of aldolase B leads to the accumulation of fructose-1-phosphate in the liver, kidneys, and small intestine. This accumulation inhibits the breakdown of glycogen and the synthesis of glucose, leading to hypoglycemia (low blood sugar) and a range of metabolic disturbances. The inability to properly metabolize fructose can result in severe symptoms following the ingestion of fructose, sucrose, or sorbitol.

Genetics

Hereditary fructose intolerance is inherited in an autosomal recessive pattern, which means that an individual must inherit two copies of the defective gene, one from each parent, to be affected by the disorder. The gene responsible for this condition is the ALDOB gene, located on chromosome 9. Mutations in the ALDOB gene lead to the production of a nonfunctional aldolase B enzyme.

Symptoms

Symptoms of hereditary fructose intolerance typically appear when an infant begins to consume foods containing fructose or sucrose. Common symptoms include:

• Severe abdominal pain
• Vomiting
• Hypoglycemia
• Jaundice
• Hepatomegaly (enlarged liver)
• Failure to thrive

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, family history, and genetic testing. A liver biopsy may also be performed to measure aldolase B activity, although this is less commonly done due to the availability of genetic testing.

Management

The primary treatment for hereditary fructose intolerance is the strict avoidance of fructose, sucrose, and sorbitol in the diet. This involves careful reading of food labels and awareness of foods that naturally contain these sugars. With proper dietary management, individuals with HFI can lead healthy lives without complications.

Prognosis

With early diagnosis and strict dietary management, individuals with hereditary fructose intolerance can have a normal life expectancy and good quality of life. However, failure to adhere to dietary restrictions can lead to serious health complications.

Also see

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