Fructose Intolerance

Background and History: 

This is a rare disorder of intolerance to fruits and sugars containing fructose and sucrose.

Clinical Correlations: 

Fructose intolerance is usually manifest early in life when infants are weaned and introduced to diets containing certain sugars found in fruits.  They may have severe abdominal pain and vomiting and a few develop seizures and become unresponsive due to low blood sugar.  Failure to grow normally is common with physical retardation.  Chronic exposure to these sugars leads to liver and kidney damage.  Most affected individuals develop a protective aversion to fruits and sweet drinks.

Several patients have been noted to have significant cataracts in the first decade of life


This is an autosomal recessive disorder requiring a mutation inherited from both parents.  With few exceptions, both parents are clinically normal but each of their children has a 25% risk of inheriting the complete disease.

Diagnosis and Prognosis: 

Much of the organ damage can be prevented by adopting a fructose-free diet.  Strict adherence to such a diet is required for normal growth to occur.  Chronic exposure to fructose in the diet, however, leads to irreversible damage to the liver and kidneys with the risk of early death, sometimes in infancy.  Diagnosis is often challenging and requires a team approach that includes pediatricians, gastroenterologists, and metabolic experts.

Additional Information
Autosomal recessive