Hereditary fructose intolerance

Injury	Disease	Nutrition	Poison

Symptoms	Surgery	Test	Special Topic

Overview

Symptoms

Treatment

Prevention

Hereditary fructose intolerance

Definition:

Hereditary fructose intolerance is a metabolic disease caused by the absence of an enzyme, aldolase B.

Alternative Names:
Fructosemia; Fructose intolerance; Fructose aldolase B-deficiency
Causes, incidence, and risk factors:

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Fructose is a fruit sugar that naturally occurs in the body. Man-made fructose is used as a sweetener in many foods, including baby food and drinks. Hereditary fructose intolerance is an autosomal recessive disease. It may be as common as 1 in 20,000 in some European countries.

In fructose-intolerant people, ingestion of fructose (fruit sugar) and sucrose (cane or beet sugar, table sugar) produces complicated chemical changes that cannot be corrected because of the absence of the enzyme aldolase B. Ingestion of fructose causes profound hypoglycemia (low blood sugar) and progressive liver damage. The body is unable to convert its energy storage material, glycogen, into glucose. Subsequently, the blood sugar falls (hypoglycemia). In addition, blocks in the metabolic pathway of fructose processing will cause a build-up of substances that damage the liver.

Hereditary fructose intolerancemay be relatively mild or a very severe disease. In the severe form, even eliminating fructose and sucrose from the diet may not prevent progressive liver disease.