You open your genetic test report and find the phrase “variant of uncertain significance (VUS).” It sounds technical and can feel unsettling. “Did the test find a disease gene?” and “Should my children be tested?” are common questions.
The short answer is that a VUS is not a positive result. A DNA difference has been found, but the evidence is not strong enough to determine whether it causes disease. The report is describing the current limit of knowledge, not delivering a diagnosis.
What is a VUS?
Human DNA contains many normal differences. To classify a variant, laboratories consider how common it is in the population, whether it appears in affected people, whether it tracks with disease in families, how it may alter a protein, and what scientific studies show.
If the evidence cannot place the variant in a “pathogenic/likely pathogenic” or “benign/likely benign” category, it is reported as uncertain. It is the middle category in the five-tier ACMG/AMP framework.
Why is a VUS not a positive result?
A positive genetic result identifies a pathogenic or likely pathogenic variant with substantial evidence linking it to a condition. That evidence is missing for a VUS. The American College of Medical Genetics and Genomics explicitly states that a VUS should not be used in clinical decision-making.
A VUS alone should therefore not diagnose a heart condition, start medication, trigger an ICD, or justify surgery. Decisions still rely on symptoms, ECG findings, imaging, and family history.
Should relatives be tested for a VUS?
Testing healthy relatives simply to divide them into “carrier” and “non-carrier” groups is generally inappropriate. Because the variant’s meaning is unknown, a carrier cannot be labeled affected and a non-carrier cannot be declared safe.
In selected cases, a genetics team and laboratory may study certain relatives to gather evidence that could help classify the variant. That is a controlled segregation study, not routine predictive cascade testing.
Can a VUS change over time?
Yes. As case reports, family data, population databases, and laboratory evidence accumulate, a VUS may be reclassified. It can move toward benign or toward pathogenic. Many reclassifications move toward benign or likely benign, but no reliable timetable exists for an individual variant.
Current HCM guidance also notes the value of periodically reconfirming reported variant classifications. Keep the complete report and make sure the testing laboratory has current contact information.
What should you do after receiving a VUS?
- Keep the full report. Preserve the exact technical variant name and classification date, not just a screenshot.
- Revisit why the test was ordered. Was there a strong clinical suspicion, or was the finding incidental on a broad panel?
- Do not let the report replace clinical care. Necessary ECGs, imaging, lipid testing, or vascular follow-up continue independently of the VUS.
- Agree on a review plan. Ask about the laboratory’s update policy and when the finding might be reassessed.
- Report new family information. A new diagnosis, sudden death, or detailed autopsy may add useful evidence.
Is a negative result the same as a VUS?
No. A negative result means that no reportable disease-causing change was identified in the genes tested. A VUS means that a change was found but its meaning is unknown. In both situations, strong clinical findings may still justify follow-up.
We compare positive, negative, and uncertain findings in our guide to cardiovascular genetic test interpretation.
Does a bigger panel always give a better answer?
No. The more genes a panel includes, the greater the chance of finding uncertain variants. Adding genes with weak relevance to the patient’s condition can create ambiguity rather than useful information. The best test is not necessarily the biggest panel; it is the one built around a clear clinical question and well-established disease genes.
Takeaway
A VUS is not a diagnosis. It is a classification that says current evidence is insufficient. The sensible response is to continue appropriate clinical care, keep the report, and arrange reassessment when relevant—not to make irreversible decisions in a hurry.
For an integrated review of a genetic report and cardiovascular findings, visit our genetic testing and counseling page or request an appointment.
Frequently asked questions
Does a VUS mean I have heart disease or cancer?
No. Its relationship to disease has not been established, so it cannot make a diagnosis by itself.
Do I need surgery because of a VUS?
A VUS alone should not be used to justify surgery or another treatment.
When should my report be reviewed again?
There is no universal interval. Timing depends on the condition, laboratory policy, and new information from the family.
Scientific sources: ACMG/AMP standards for sequence variant interpretation; Variant reclassification and clinical implications; MedlinePlus guide to interpreting genetic test results.
This article is for general education. A genetic report must be interpreted in the context of the reason for testing, clinical findings, and family history.
