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Genetic and Rare Diseases Information Center (GARD)

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Hereditary fructose intolerance

Other Names for this Disease
  • ALDOB deficiency
  • Aldolase B deficiency
  • Fructose intolerance, hereditary
  • Fructose-1,6-bisphosphate aldolase B deficiency
  • Fructose-1-phosphate aldolase deficiency
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Your Question

My grandson has been diagnosed with hereditary fructose intolerance. The family has not been able to see a dietician, and they are having a hard time finding good recipes. Please give me some info so I can help them.

Our Answer

We have identified the following information that we hope you find helpful. If you still have questions, please contact us.

What is hereditary fructose intolerance (HFI)?

Hereditary fructose intolerance (HFI) is a metabolic disease caused by the absence of an enzyme called aldolase B. In people with HFI, ingestion of fructose (fruit sugar) and sucrose (cane or beet sugar, table sugar) causes severe hypoglycemia (low blood sugar) and progressive liver damage. In addition, blocked processing of fructose will cause a build-up of substances that damage the liver. HFI may be relatively mild or a very severe disease, and treatment involves eliminating fructose and sucrose from the diet. In the severe form, eliminating these sugars from the diet may not prevent progressive liver disease.[1]
Last updated: 3/17/2009

What are the symptoms of hereditary fructose intolerance (HFI)?

The symptoms of HFI include:[1]

  • Poor feeding as a baby
  • Irritability
  • Increased or prolonged neonatal jaundice
  • Vomiting
  • Convulsions
  • Excessive sleepiness
  • Intolerance for fruits
  • Avoidance of fruits and fructose/sucrose-containing foods
  • Doing well after eating foods without fructose/sucrose

The early symptoms of fructose intolerance may resemble those of galactosemia: irritability, jaundice, vomiting, convulsions and an enlarged liver and spleen. Later problems relate more to liver disease.[1]

Last updated: 2/17/2009

What causes hereditary fructose intolerance (HFI)?

HFI is caused by alterations (mutations) in the ALDOB gene.[2] This gene provides instructions for making an enzyme called aldolase B or fructose 1-phosphate aldolase. Mutations in the ALDOB gene prevent the body from producing aldolase B, which is needed to break down fructose.
Last updated: 2/17/2009

How is hereditary fructose intolerance (HFI) inherited?

HFI is inherited in an autosomal recessive manner, which means alterations (mutations) are present in both copies of the ALDOB gene.[1] People with this condition often do not have a family history of fructose intolerance. It may be as common as 1 in 20,000 in some European countries.[1]
Last updated: 2/17/2009

How is hereditary fructose intolerance (HFI) treated?

Complete elimination of fructose and sucrose from the diet is an effective treatment for most people,[1] although this can be challenging. More information on treatment for HFI is available from the HFI Laboratory at Boston University at the following link. This page includes information on what people with HFI can and cannot eat.

Additional information on foods to avoid if you have HFI is available from the Mayo clinic.
Last updated: 2/17/2009

What specialists can help diagnose and treat hereditary fructose intolerance (HFI)?

A dietician can often be very useful in providing guidance regarding the dietary management of HFI. The American Dietitian Association can help you locate a dietician in your area.

American Dietetic Association
120 South Riverside Plaza, Suite 2000
Chicago, Illinois 60606-6995
Consumer nutrition information and referrals
Toll-free: 1-800-366-1655
Public Web site:

Since HFI is a genetic condition, we suggest that you contact a genetics clinic to discuss this information with a genetics professional. To find a genetics clinic near you, we recommend contacting your primary doctor for a referral. The following online resources can also help you find a genetics professional in your community:

  * GeneClinics - A searchable directory of US and international genetics and prenatal diagnosis clinics. To locate genetics clinics in the United States, go to the following link and click on 'Clinic Directory' to find a genetic service close to you.  To locate genetics clinics outside of the United States, go the following link, click on 'Clinic Directory', and click on 'International Clinic Directory Search'.

  * ResourceLink - A database of genetics counseling services, searchable by location, name, institution, type of practice, or specialty. Hosted by the National Society of Genetic Counselors.

  * Genetic Centers, Clinics, and Departments - A comprehensive resource list for genetic counseling, including links to genetic centers and clinics, associations, and university genetics departments. Hosted by the University of Kansas Medical Center.

The American Society of Human Genetics (ASHG) is a professional organization of research and clinical geneticists. The ASHG maintains a database of these geneticists, some of which live outside of the United States. If you are interested in obtaining a list of the geneticists in your country, some of which may only be researchers and may not offer medical care, please visit the following hyperlink, enter 'YOUR COUNTRY'S NAME' in the 'Country' search box, and click on 'Click to Begin Search'.
Last updated: 3/17/2009