Is Fructose Intolerance hereditary?

Hereditary Fructose Intolerance (HFI) is a strictly genetic condition caused by mutations in the ALDOB gene, meaning it is inherited from parents rather than acquired. It follows an autosomal recessive inheritance pattern, which requires an individual to inherit one defective copy of the gene from each parent to manifest the disorder.

Is Hereditary Fructose Intolerance strictly genetic?

Yes, Hereditary Fructose Intolerance is a genetic metabolic disorder. It is not caused by lifestyle or environmental factors. Because it is an autosomal recessive condition, parents who are carriers (each having one mutated ALDOB gene) typically show no symptoms, but they have a 25% chance with each pregnancy of having a child with Hereditary Fructose Intolerance.

How is the condition inherited?

The ALDOB gene provides instructions for making the enzyme aldolase B, which is essential for breaking down fructose. When both copies of the gene are mutated, the body cannot process fructose, leading to the clinical manifestations of Hereditary Fructose Intolerance. De novo (spontaneous) mutations in this gene are extremely rare; almost all cases are inherited from parents who are asymptomatic carriers.

What are the testing and counseling options?

Genetic testing for Hereditary Fructose Intolerance is highly effective and is considered the gold standard for diagnosis, often replacing the need for more invasive liver biopsies. Clinical geneticists recommend the following steps for families:

• Molecular Genetic Testing: Sequencing the ALDOB gene to identify specific pathogenic variants.


• Carrier Screening: Recommended for relatives of a person diagnosed with Hereditary Fructose Intolerance.


• Genetic Counseling: Essential for couples planning a family who have a known family history of the disease to discuss reproductive risks.


• Prenatal Diagnosis: Available through amniocentesis or chorionic villus sampling (CVS) if the specific familial mutations are known.

Currently, 93 people with Hereditary Fructose Intolerance have joined the DiseaseMaps community, sharing their experiences with managing this lifelong genetic condition.

Next steps

• Consult a clinical geneticist to discuss ALDOB gene sequencing.


• Speak with a metabolic dietitian to manage fructose intake safely.


• Connect with the 93 members of the DiseaseMaps.org community to share experiences.


• Request a referral to a metabolic specialist for ongoing management.

Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Hereditary Fructose Intolerance.


• Orphanet: Hereditary Fructose Intolerance (ORPHA:342).


• Online Mendelian Inheritance in Man (OMIM): Aldolase B (ALDOB) gene entry #229600.


• National Organization for Rare Disorders (NORD): Rare Disease Database.