You've been told your homocysteine is high — but nobody tested whether your genes might be making it impossible to metabolize it properly.
Whole genome sequencing identifies both common polymorphisms and rare pathogenic variants in MTHFR, revealing the genetic basis of elevated homocysteine and enabling targeted supplementation strategies.
MTHFR Gene Mutation
MTHFR encodes methylenetetrahydrofolate reductase, an enzyme critical for converting folate into its active form and regulating one-carbon metabolism — the pathway that converts the amino acid homocysteine into methionine. Two common polymorphisms exist: C677T, which reduces enzyme activity to roughly 30% of normal in homozygotes, and A1298C, which reduces activity to about 60%. In the rare severe form, biallelic pathogenic variants cause near-complete loss of enzyme function, leading to severe hyperhomocysteinemia and neurological complications.
Approximately 10% of North Americans are homozygous for the C677T polymorphism. Both polymorphisms are prevalent across populations with ethnogeographic variation. When folate status is low, carriers of these polymorphisms may develop mildly elevated homocysteine, which is associated with increased cardiovascular risk and, in women, modestly increased risk of neural tube defects in offspring. The rare severe form of MTHFR deficiency affects approximately 1 in 10,000 to 50,000 people globally and follows autosomal recessive inheritance.
Understanding MTHFR variants has immediate clinical implications. For individuals with elevated homocysteine, identifying a pathogenic MTHFR variant guides personalized folate and B-vitamin supplementation strategies. For carriers with the common C677T polymorphism, confirming the genotype informs family planning decisions and prenatal counseling. For severe deficiency, a genetic finding enables betaine therapy initiation, confirms the diagnosis, and guides cascade testing in family members — each sibling of an affected individual has a 25% recurrence risk.
MTHFR variants include both common polymorphisms (C677T and A1298C) and rare pathogenic variants causing severe deficiency — each with different enzymatic impact and clinical consequences.
Standard MTHFR testing checks only two polymorphisms. Research shows it misses over 100 rare pathogenic variants that cause severe homocystinuria.
Rare variants hide in the full gene sequence
Clinical MTHFR testing typically screens only the two common polymorphisms (C677T and A1298C), missing the over 100 rare pathogenic variants in MTHFR that cause severe homocysteinuria and severe methylation defects. Current clinical guidelines (ACMG, American College of Gastroenterology) recommend against routine MTHFR polymorphism testing for thrombophilia, noting that homocysteine level measurement alone is more actionable than genotype. Whole genome sequencing captures the full coding and non-coding sequence, identifying both common polymorphisms and rare pathogenic variants simultaneously.
A finding guides family screening and personalized treatment
When a pathogenic MTHFR variant is confirmed, it enables several clinical actions: targeted folate and B-vitamin supplementation based on the specific enzymatic defect, informed prenatal counseling if the variant affects folate metabolism (reducing neural tube defect risk), family cascade testing to identify other carriers (each sibling of a rare-variant carrier has a 25% recurrence risk), and in severe deficiency, initiation of betaine therapy. For women planning pregnancy with identified C677T homozygosity, periconceptional folate supplementation is now standard care.
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 MTHFR Gene Mutation 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
