Antidepressant Response — CYP2D6 and CYP2C19 variants determine whether an antidepressant reaches therapeutic levels, causes toxicity, or never works at the prescribed dose.
Whole genome sequencing provides complete CYP2D6 and CYP2C19 diplotypes — the two genes that govern the metabolism of most commonly prescribed SSRIs, SNRIs, and tricyclic antidepressants — before the first prescription is written.
Antidepressant Response — CYP2D6 & CYP2C19
The pharmacological response to antidepressants varies dramatically between individuals, and a substantial proportion of that variance is genetically determined. Two cytochrome P450 enzymes — CYP2D6 and CYP2C19 — are responsible for the primary metabolic clearance of the majority of antidepressants in widespread clinical use. CYP2D6 metabolizes fluoxetine (Prozac), paroxetine (Paxil), venlafaxine (Effexor), duloxetine (Cymbalta), tricyclic antidepressants including amitriptyline and nortriptyline, and several antipsychotics used as adjuncts in treatment-resistant depression. CYP2C19 metabolizes citalopram (Celexa), escitalopram (Lexapro), sertraline (Zoloft), amitriptyline, and clomipramine.
CYP2D6 metabolizer phenotypes span a wide spectrum. Poor metabolizers (PM) carry two loss-of-function alleles and cannot clear CYP2D6-substrate antidepressants at normal rates — they accumulate drug at standard doses, experiencing toxicity including QT prolongation, serotonin syndrome risk, and adverse effects that lead to drug discontinuation. Ultra-rapid metabolizers (UM) carry duplicate or multiply duplicated functional CYP2D6 alleles and clear drugs so rapidly they never achieve therapeutic plasma concentrations at standard dosing. Intermediate metabolizers have an attenuated intermediate phenotype. CYP2C19 PMs accumulate escitalopram and citalopram — the FDA issued a dose-limiting guidance for citalopram specifically referencing CYP2C19 poor metabolizer status in 2012, capping the maximum dose to reduce QTc prolongation risk.
CPIC guidelines (Level A) provide prescribing recommendations for CYP2D6 and CYP2C19 across multiple antidepressants: alternatives or dose adjustments are recommended for PMs and UMs for tricyclic antidepressants; dose reductions are recommended for CYP2C19 PMs on citalopram and escitalopram; and alternative agents are recommended for CYP2D6 PMs on paroxetine and fluoxetine. Psychiatric pharmacogenomics testing is increasingly standard of care for treatment-resistant depression — studies show that genotype-guided antidepressant selection reduces medication switches and reduces time to remission compared to standard trial-and-error prescribing.
CYP2D6 has over 100 named star alleles with highly variable activity. Gene copy number variation — including complete gene deletions and multiplications — is common and determines the ultra-rapid and poor metabolizer phenotypes that have the most dramatic antidepressant response consequences.
Standard psychiatry genetic panels test a limited set of CYP2D6 and CYP2C19 variants. Whole genome sequencing resolves the complete star-allele diplotype — including copy number variants and rare alleles missed by fixed panels.
CYP2D6 gene copy number variants require genome-level detection
CYP2D6 ultra-rapid metabolizer status most commonly arises from gene duplication — an individual carries 3, 4, or more copies of a functional CYP2D6 allele. Standard SNP-based pharmacogenomics panels can identify the major loss-of-function alleles but often cannot reliably quantify CYP2D6 copy number or distinguish genotypes with intermediate copy numbers. Whole genome sequencing provides both variant identification and copy number analysis across the CYP2D6 locus, enabling complete diplotype assignment including the duplication alleles that define ultra-rapid metabolizer status — the phenotype where standard antidepressant doses fail entirely.
One genome result covers every antidepressant you may ever be prescribed
Psychiatric medication management is rarely a single-drug decision. Most patients with depression try multiple agents over their lifetime — SSRIs, SNRIs, augmentation with atypical antipsychotics, TCAs for refractory cases. Each new drug introduces a new pharmacogenomic question. A complete CYP2D6 and CYP2C19 diplotype from whole genome sequencing answers the metabolizer question for all CYP2D6 and CYP2C19 substrate medications simultaneously and permanently — the result applies to every future prescribing decision, not just the current one.
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.
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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 Antidepressant Response — CYP2D6 & CYP2C19 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.
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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
