Hereditary Fructose Intolerance (ALDOB)

Hereditary fructose intolerance is an autosomal recessive disorder that is caused by pathogenic variants in the gene ALDOB. While it is found in populations worldwide, it is more prevalent in Caucasians. Pathogenic ALDOB variants result in a deficiency of the enzyme that breaks down the sugar fructose. As fructose is not found in milk, there are usually no symptoms until the time that sugars are added to the diet. Ingestion of fructose will cause pain, vomiting and hypoglycemia. If fructose is not removed from the diet, patients can develop seizures, intellectual disability and severe liver and kidney problems, and death. For most patients, early diagnosis and careful dietary management can result in a symptom-free, normal lifespan. Currently, it is not possible to predict the severity of the disease based on the genotype.

For information about carrier frequency and residual risk, please see the residual risk table.