Medical Oncologist
CION Cancer Clinics
'Variant of uncertain significance' in a germline report | CION Cancer Clinics
A variant of uncertain significance, or VUS, means a genuine spelling difference was found but there is not yet enough evidence to call it harmful or harmless. It is not a positive result and it does not change your screening or treatment. This page explains why VUS findings happen, what labs do with them afterwards, and why they are more common in Indian families. At CION Cancer Clinics in Hyderabad, our oncologists review your family history with you and guide you to the right genetic counselling and testing.
NG
Medically reviewed by Dr. Naresh GunduConsultant Medical Oncologist · MBBS, DNB (Internal Medicine), DM (Medical Oncology, AIIMS) · last reviewed September 2026, next review due September 2027
17+specialists on panel
15,000+patients treated
35+centres across Telangana & AP
4.8★ / 800+Google rating
On this page
- What is a 'variant of uncertain significance'?
- Four things a VUS does not mean
- What happens to a VUS after your report is issued
- Words that come with a VUS
- A VUS and a pathogenic result, compared
- Why a VUS turns up more often for some families than others
- Four things families assume about a VUS
- Common questions about a VUS result
The short answer
What is a 'variant of uncertain significance'?
A variant of uncertain significance, usually written as VUS, means the laboratory found a genuine spelling difference in a gene but does not yet have enough evidence to say whether it causes harm or is harmless. It is not a positive result, not a negative result, and not a diagnosis of anything. It is an honest "we do not know yet".
The most confusing line on any report
Of the five classifications a report can carry, a VUS causes the most worry for the least reason. Families often see a strange-sounding gene name attached to the word "variant" and assume the worst. In fact a VUS carries no medical action of its own. Nothing changes in your screening or treatment because of it.
Why laboratories report it at all
A laboratory reports every genuine spelling difference it finds in the genes it tests, including the ones it cannot yet classify with confidence, so that nothing is quietly hidden from your file. Leaving a finding off the report entirely would be less honest than naming it and explaining plainly that its meaning is not yet known. Most people who have a broad panel of genes tested will see at least one VUS somewhere on their report, simply because so many genes are being checked at once and human genetic code varies from person to person far more than most people expect.
A VUS is not a weak positive and not a hidden warning. It is a finding still waiting on more evidence.What a VUS is not
Four things a VUS does not mean
Not a diagnosis
It does not tell you or a relative that you have, or will get, cancer. It is a note about one uncertain spelling difference, nothing more.
Not a positive result
A VUS is not counted as a positive finding. Family history remains the guide for screening, not this line on the report.
Not evidence for relatives
Relatives are not usually offered testing for a VUS, because there is nothing established yet to test them for.
Not a reason for surgery
Preventive surgery is planned around confirmed pathogenic or likely pathogenic findings. A VUS on its own is never the basis for that decision.
Not sure whether this applies to you?
Ask an oncologistBehind the scenes
What happens to a VUS after your report is issued
It is logged, not forgotten
The laboratory keeps a record of every VUS it has reported, so it can be revisited as new evidence appears.
Other laboratories add their own findings
As other centres see the same change in their own patients, that evidence accumulates in shared databases.
Family studies may be offered
Testing close relatives for that exact change, and seeing whether it lines up with who has cancer, can add useful evidence.
The classification is periodically reviewed
Many VUS findings eventually move to benign. Some move to pathogenic. Some remain uncertain for a long time, which is normal.
On your report
Words that come with a VUS
- Variant of uncertain significance
- A genuine spelling difference the laboratory cannot yet classify as harmful or harmless.
- Reclassification
- A later review that moves a VUS to a firmer tier as evidence grows, in either direction.
- Population database
- A large reference collection used to check how common a change is in people with no cancer history.
- Underrepresented ancestry
- A population with fewer people included in the reference databases so far, which makes some of their variants harder to classify confidently.
- ClinVar
- The shared database where laboratories record classifications, including ongoing VUS findings, so evidence can build across centres.
- Segregation study
- Checking whether a variant is found consistently in affected relatives and absent in unaffected ones.
Leave a number, we will call you
One field. No form to fill in, and no charge for the call.
Side by side
A VUS and a pathogenic result, compared
Variant of uncertain significance
Pathogenic
Not enough evidence yet to classify either way
Strong, consistent evidence of harm
Screening follows family history alone
Screening may start earlier because of this result
Relatives are not usually offered testing for it
Relatives can be offered a targeted test
Reviewed periodically as evidence accumulates
Rarely revised once confirmed
A point worth knowing in India
Why a VUS turns up more often for some families than others
How confidently a laboratory can classify a variant depends heavily on how many people carrying that exact change have already been studied. The large reference databases behind this system were built mostly from people of European ancestry. Families from South Asia, and Indian families in particular, are still underrepresented in that evidence base.
What this means in practice
A change that would be confidently classified in a well-studied population can land as uncertain in an Indian family simply because fewer people carrying it have been tested and published on so far. This is a gap in the world's evidence, not a fault in the test itself, and it is closing as more laboratories in India and the wider region contribute their own findings.
What this does not mean for you
It does not mean your test was done poorly, or that an Indian laboratory's classification counts for less than one from elsewhere. It means the evidence for that specific change is still being built, which is exactly what a VUS classification is designed to say plainly rather than guess past. As more Indian laboratories and hospitals contribute their own patients' results to the shared databases, changes that are common in this region will be classified with the same confidence as changes already well studied elsewhere, and some of that progress is already visible year on year.
Commonly believed
Four things families assume about a VUS
"A VUS is basically a soft positive result."
It carries no medical action of its own. It is treated as unclassified, not as a lesser version of pathogenic.
"My relatives should be tested for it just in case."
There is usually nothing established yet to test them for. Family testing is generally offered once, and if, a variant is reclassified with confidence.
"The laboratory made a mistake by not giving a clear answer."
Reporting a VUS honestly, rather than guessing, is the laboratory doing its job correctly. A confident wrong answer would be far worse than an honest uncertain one.
"Since it might be bad, I should consider preventive surgery now."
A VUS is never, on its own, the basis for a preventive surgery decision. That step is reserved for confirmed pathogenic or likely pathogenic findings.
Questions we are asked
Common questions about a VUS result
Does a VUS mean I have a raised cancer risk?
Not on its own. It means one spelling difference was found and cannot yet be classified. Your risk continues to be judged mainly by your family history until that changes.
Should my children or siblings be tested for the same VUS?
Usually not. Testing relatives for an unclassified finding rarely adds anything useful, since there is nothing confirmed yet to act on.
Will I be told if my VUS is ever reclassified?
You should be. Ask your laboratory or counsellor how and when you would be contacted, since practices vary, and make sure your contact details stay current with them.
Can I ask the laboratory to investigate my VUS further?
Sometimes, for example by offering to test other relatives to build a family pattern. Ask your counsellor whether that kind of follow-up study is available for your specific variant.
Why did I get a VUS when a relative with cancer tested clearly positive?
You may carry a different, unrelated change, or the shared change simply has not been studied enough to classify confidently yet. Your counsellor can look at both results together.
Is a VUS more common in certain communities?
Yes. Populations that are underrepresented in the world's reference databases, including many Indian communities, see this classification more often, simply for lack of accumulated evidence.
Should I search my exact VUS online?
It rarely helps and can mislead, since public listings do not explain context the way a counsellor can. Ask your counsellor to check it in the proper databases with you instead.
Who can tell me what my specific VUS means?
Nobody can tell you with confidence yet, and a genetic counsellor is best placed to explain exactly what is and is not known about your particular finding.
Your Specialists
Meet CION's oncologists. Bring your family history or genetic report to them.
Our medical oncologists see people with a strong family history of cancer, arrange genetic counselling and testing where it fits, and plan the checks that follow.
Medical Oncologist
Dr. C. Raghavendra Reddy
MBBS(Gold Medal), DNB(General Medicine), DM(Medical Oncology)(Gold Medal)
Medical Oncologist
Dr. Bharati Devi Gorantla
MBBS, MD(General Medicine), DM(Medical Oncology)(Adyar,Chennai), ECMO, MRCP SCE(UK)
Medical Oncologist
Dr. Owais Mohammed
MBBS, MD (General Medicine), DrNB (Medical Oncology), ECMO, MRCP SCE (Medical Oncology) (UK)
Medical Oncologist
Medical Oncologist
Want a specific doctor for your case? Mention them when booking.
Book Free ConsultationBook an appointment with our specialist
Share your name and number — we'll call you back within 30 minutes to schedule your consultation.
Sources
- MedlinePlus Genetics — What do the results of genetic tests mean?
- National Cancer Institute — Genetic Testing for Inherited Cancer Susceptibility Syndromes
- Cancer Research UK — Inherited cancer genes and increased cancer risk
- NHS — Predictive genetic tests for cancer risk genes
This page is general information, not a prescription. Do not change or stop any treatment based on what you read here. If anything is worrying you, contact your own treating team — or call our helpline and we will help you reach the right specialist.
Keep reading
Related pages
Why a VUS should not change your treatmentWhy this finding is not acted on clinicallyThe five variant classifications explainedWhere a VUS sits among the other four tiersVariant reclassification: when a result changes years laterWhat happens if your VUS is ever resolvedShould you search for your variant online?Why looking it up yourself rarely helps
Talk to us
Given a VUS result and not sure what it means for you?
Tell us the gene named on your report. We will explain plainly what is, and is not, known about a finding like yours. One helpline serves every CION centre.