Hereditary Fructose Intolerance — where a single dietary change (strict fructose avoidance) completely prevents liver failure, kidney damage, and hypoglycemic episodes that occur with each exposure to fructose, sucrose, or sorbitol.
Whole genome sequencing identifies all ALDOB variants — including the three common European mutations that account for 85% of alleles — providing the molecular diagnosis that replaces the dangerous intravenous fructose tolerance test.
Hereditary Fructose Intolerance
Hereditary fructose intolerance (HFI) is an autosomal recessive disorder caused by pathogenic variants in ALDOB (aldolase B, chromosome 9q31.1). Aldolase B is the liver, kidney, and intestinal isoform of aldolase that cleaves fructose-1-phosphate during fructose metabolism. ALDOB deficiency causes fructose-1-phosphate accumulation after ingestion of fructose, sucrose, or sorbitol — trapping intracellular phosphate, inhibiting gluconeogenesis, and causing acute hypoglycemia, nausea, vomiting, and progressive liver and kidney damage. Carrier frequency is approximately 1 in 55-80 in European populations, with clinical prevalence of approximately 1 in 20,000-30,000.
HFI typically presents during weaning, when fruits, juices, and sucrose-containing foods are introduced to the infant's diet. Acute symptoms include nausea, vomiting, abdominal pain, and hypoglycemia after fructose-containing meals. Chronic fructose exposure produces hepatomegaly, jaundice, coagulopathy, renal tubular dysfunction, and failure to thrive. Many HFI patients develop a natural aversion to sweet foods and fruits — this self-protective behavior can lead to diagnostic delay, as the patient avoids the trigger without understanding why. Adults with undiagnosed HFI frequently report lifelong 'fruit intolerance' and are misdiagnosed with food allergies, IBS, or functional GI disorders.
Treatment is strict dietary avoidance of fructose, sucrose, and sorbitol — completely preventing all symptoms and tissue damage when maintained consistently. Hidden fructose sources (medications, IV fluids containing sorbitol, infant formula, processed foods) must be identified and eliminated. The historical diagnostic test — intravenous fructose tolerance test — carries risk of severe hypoglycemia and hepatic damage and has been largely replaced by molecular ALDOB genotyping. Three common ALDOB variants (p.Ala149Pro, p.Ala174Asp, p.Asn334Lys) account for approximately 85% of HFI alleles in European populations.
IV fluids and medications containing fructose, sucrose, or sorbitol can cause life-threatening hypoglycemia in HFI patients. Medical alert identification and complete medication review are essential after diagnosis.
The historical fructose tolerance test is dangerous. Molecular ALDOB genotyping has replaced it as the diagnostic standard — safe, definitive, and simultaneously providing carrier status for family members.
Molecular diagnosis replaces the dangerous IV fructose challenge — ALDOB genotyping is both safer and more definitive
The intravenous fructose tolerance test required administering the exact substance that causes toxicity in HFI patients — producing predictable hypoglycemia, nausea, and hepatic injury, with rare reports of severe complications. Molecular ALDOB genotyping provides a definitive diagnosis from a blood sample without any fructose exposure. The three common European ALDOB variants (p.Ala149Pro, p.Ala174Asp, p.Asn334Lys) account for approximately 85% of disease alleles and are identified by whole genome sequencing alongside the remaining 15% of rare ALDOB variants that population-specific panels may miss.
Many adults with HFI are undiagnosed — labeled with 'food allergies' or IBS because they self-select away from sweet foods
HFI patients often develop a natural aversion to sweet foods, fruits, and juice in early childhood. By adulthood, they have unconsciously eliminated most dietary fructose and present with only intermittent GI symptoms from hidden fructose exposure. These patients are frequently diagnosed with food allergies, functional dyspepsia, or irritable bowel syndrome. Molecular diagnosis through whole genome sequencing — which evaluates ALDOB alongside thousands of other genes — can incidentally identify HFI in patients who were never specifically tested, finally explaining their lifelong dietary pattern.
Your full DNA (not just a part of it)
Traditional genetic testing looks at narrow sets of genes, missing most parts of your genome. We sequence your full genome — every gene and every region between genes.
Comprehensive insights and specialized reports
Easy to read and with answers you and your doctor can act on. Not a file to interpret — 200+ clinical reports, organized by category.
Your test becomes more valuable every year
Your DNA does not change, but genome science is accelerating. Every month, new variant-disease associations are discovered. We validate these findings and update your reports automatically. Your test becomes more valuable every year.
The results doctors bring to their hardest cases.
Forty years of uncertainty. One test.
A patient had spent decades in the UK healthcare system without a diagnosis. Dante data, accepted by NHS clinical teams at Queen Elizabeth University Hospital Glasgow, identified Noonan Syndrome and a RUNX1 leukemia-associated variant that had gone undetected. After 40 years, they finally had an answer.
A complete read delivers a complete picture.
A patient came to Dante to investigate periodic paralysis. Reading the complete genome identified a concurrent hereditary cardiac finding — Brugada syndrome — that their doctor confirmed with an ECG. The result also explained a family member's unresolved cardiac history. One test. Every answer in it.
Sequenced in 2019. The data worked in 2021.
Jennifer sequenced her genome with Dante two years before her breast cancer diagnosis. When treatment began, Dante's pharmacogenomics data showed her prescribed chemotherapy would cause serious adverse effects. Her doctor selected an alternative — and she started effective treatment from day one.
Every genetic question deserves a complete answer.
Whether you are searching for answers today or protecting your health for tomorrow, a complete read of your entire genome is the only place to start.
It runs in your family. Now you can know if it runs in your genes.
Your genome contains inherited variants associated with medical conditions like cardiac, cancer, and neurological. We read all of them — with the clinical depth to give the result meaning.
Learn more →When traditional lab tests say you're fine. And you know you're not.
Standard diagnostic tests check for a pre-selected set of answers. We sequence your full DNA — including parts that no test was designed to check. If the answer is in your genome, we will help you find it.
Learn more →Your diagnosis may be right. Your treatment plan may be incomplete.
Your genes determine which treatments are most likely to work — and which are not. We give your doctor the tools and insights to inform your treatment plan.
Learn more →You want to know before something forces the question.
Some people don't wait for a diagnosis or a family history to act. Whole genome sequencing gives you the complete genetic picture now — so you and your doctor can make informed decisions before anything becomes urgent.
Learn more →You already took a DNA test. Here's what it couldn't tell you.
Most consumer DNA tests read less than 0.1% of your genome. We read all of it.
Learn more →Clinical-grade results. Chosen by individuals, trusted by doctors for their most complex cases.
Dante Genome Test helped specialists at a UK national acute hospital in the identification of Noonan Syndrome and a rare leukemia-associated genetic variant that had gone undetected. That result changed the medical care of the patient.
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Common questions about whole genome sequencing.
What is the difference between whole genome sequencing and a targeted genetic test?
Targeted genetic tests — including standard hereditary cancer panels — read a pre-defined list of known variants in a specific set of genes. They are designed to find what they already know to look for. Whole genome sequencing reads your entire genome: all 6 billion base pairs, every gene, every region between genes. A Mayo Clinic study published in JAMA Oncology found that standard testing guidelines missed more than half of patients with inherited cancer mutations. Genome Test does not have a fixed list.
What will I receive when my results are ready?
Your Dante Genome delivers 200+ physician-ready reports organized by clinical category — hereditary cancer, cardiac conditions, rare diseases, pharmacogenomics, carrier status, and more. Reports are delivered to your secure Genome Manager and are formatted for direct clinical use. Your genome data is permanently retained and re-analyzed automatically as science advances.
What happens if a clinically significant variant is found?
If a pathogenic or likely-pathogenic variant is identified, it will be clearly flagged in your physician-ready report with clinical context, published evidence, and recommended next steps. We recommend sharing any clinically significant finding with your physician or a genetic counselor, who can guide decisions about surveillance, risk reduction, or cascade testing for family members.
How is this different from a consumer DNA test like 23andMe or AncestryDNA?
Consumer DNA tests use genotyping chips that read less than 0.1% of your genome — a tiny pre-selected set of common variants. They are optimized for ancestry and population-level traits, not clinical genetic findings. The Dante Genome Test sequences 100% of your genome at 30X coverage, the same standard used in clinical diagnostic settings. The two tests are not comparable in scope, methodology, or clinical utility.
How long does it take to get results, and how are they delivered?
Your collection kit ships within 48 hours of ordering. Once your sample arrives at our CLIA-certified laboratory, sequencing and analysis takes 6–8 weeks. Results are delivered securely to your Genome Manager, where you can access your reports, share them with your physician, and receive automatic updates as new findings are validated against your genome.
We work with patient advocacy groups worldwide.
Dante Labs works with patient advocacy groups of any size — for Hereditary Fructose Intolerance and other conditions, rare and common. We support groups in any country, including virtual patient advocacy groups.
We can provide customized reports, group discounts, and packages tailored for your members. Please reach out using the form and we'll be in touch within two business days.
- Custom genomic reports for your members
- Group discounts and tailored packages
- Any country — including virtual groups
- Rare and common conditions covered
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One test.
A lifetime of answers.
One kit, sent to your home. Your entire genome sequenced at the clinical standard used for diagnostic decisions. 200+ physician-ready reports delivered to your Genome Manager in 6–8 weeks — permanent and updated as science advances.
Ships within 48 hours · Results in 6–8 weeks
