Written by

Dr. Vinay Bhatia

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Reviewed by

Dr. Jasmine Kaur

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18 min read

Hereditary Breast and Ovarian Cancer Syndrome: Genes, Risk and Testing

A practical guide to inherited cancer risk, family-history assessment, BRCA and multigene testing, and what different genetic results can mean for you and your family.
Key takeaways
  • Most breast and ovarian cancers are not caused by a single inherited gene variant, but certain personal and family patterns warrant hereditary risk assessment.
  • BRCA1 and BRCA2 are important DNA-repair genes, but variants in several other genes can also raise the risk of breast, ovarian or related cancers.
  • A pathogenic variant can be inherited from either parent, and each child of a carrier usually has a 50% chance of inheriting that variant.
  • BRCA-only testing and multigene panels answer different clinical questions; broader testing may find more relevant variants but also produces more uncertain results.
  • A negative BRCA result does not always exclude hereditary cancer risk, particularly when no familial variant is known or other genes may be involved.

Hereditary breast and ovarian cancer in Indian families

Imagine that your mother had breast cancer in her early forties, her sister later developed ovarian cancer, and a cousin on the same side of the family has recently been diagnosed with breast cancer. Each diagnosis needs its own medical evaluation, but together they create a pattern that may prompt an oncologist to ask whether an inherited predisposition could be present.
Most breast and ovarian cancers are sporadic. This means they develop through genetic changes acquired during life rather than through a variant inherited at birth. Familial cancer describes more cancer in a family than expected, but the cause may be a combination of shared genes, environment, chance and incomplete information. Hereditary cancer refers more specifically to cancer predisposition caused by an inherited pathogenic or likely pathogenic gene variant.[1]
Clinicians therefore look beyond the number of relatives with cancer. The ages at diagnosis, exact tumour types, whether cancers occurred on one side of the family, and whether anyone developed more than one primary cancer can all change the assessment. The maternal and paternal sides are considered separately, and neither side should be overlooked.

What hereditary breast and ovarian cancer syndrome means

Hereditary breast and ovarian cancer, commonly shortened to HBOC, describes an inherited predisposition to breast, ovarian and certain related cancers. BRCA1 and BRCA2 are the best-known genes associated with this pattern, but they do not account for every family whose history suggests inherited risk.
An inherited predisposition is not a cancer diagnosis. It means that a person was born with a gene variant that can increase the probability of certain cancers, while additional biological changes are usually needed before a cancer develops. Some carriers never develop cancer, and the level and type of risk vary by gene, the specific variant, sex, age, family history and other factors.
Depending on the gene involved, the spectrum may extend beyond breast and epithelial ovarian cancer to fallopian-tube, primary-peritoneal, pancreatic, prostate or other cancers. Endometrial cancer—particularly when it clusters with colorectal cancer—more often raises consideration of Lynch syndrome and mismatch-repair genes than BRCA1/2. The exact diagnoses and pathology in a family therefore matter when choosing a test.[1][3]

BRCA1, BRCA2 and other hereditary cancer genes

BRCA1 and BRCA2 help cells repair certain forms of DNA damage. They act as tumour-suppressor genes, helping to maintain genomic stability and prevent damaged cells from growing unchecked. A person who inherits a harmful variant has one less fully functioning copy of the gene in many cells, which can increase susceptibility to cancer if the remaining working copy is later lost or impaired.[2]
  • PALB2 works closely with BRCA2 and can be important in hereditary breast cancer.[2]
  • TP53, PTEN and CDH1 are tumour-suppressor genes linked to specific hereditary cancer syndromes in which breast cancer may be one of several possible tumours.
  • ATM and CHEK2 are often described as moderate-penetrance breast cancer susceptibility genes, meaning they can increase risk but usually to a lesser degree than BRCA1 or BRCA2.[1]
  • RAD51C, RAD51D and BRIP1 can be relevant to ovarian cancer risk, sometimes in families where breast cancer is not the main feature.
  • Mismatch-repair genes associated with Lynch syndrome may matter when ovarian, endometrial, colorectal and other cancers occur in the same family.[1]
These genes are not interchangeable. A finding in one gene cannot be assumed to carry the same risks or clinical implications as a finding in another. Evidence is also stronger for some gene–cancer associations than for others. For this reason, panel selection and result interpretation should focus on genes with a credible connection to the personal or family history and with information that can reasonably guide clinical discussions.

How hereditary cancer risk is passed down in a family

Many major hereditary breast and ovarian cancer predispositions follow an autosomal-dominant inheritance pattern. If a parent carries one pathogenic variant, each child usually has an independent one-in-two chance of inheriting it. The probability is the same for sons and daughters, and the variant can be transmitted through either the maternal or paternal side.[1]
Men can inherit and pass on BRCA1, BRCA2 and other relevant variants even when few men in the family have developed cancer. A paternal family history may therefore include breast or ovarian cancer in the father's female relatives, or related cancers among male relatives. Small families, early deaths, adoption and limited knowledge of relatives' diagnoses can make an inherited pattern difficult to see.
Autosomal-dominant inheritance does not mean every carrier develops cancer. Penetrance is the proportion of carriers who develop a related condition, and it varies across genes and families. Incomplete penetrance can make a hereditary predisposition appear to skip a generation even though the variant may still have been passed on.[1]

When to suspect a hereditary breast or ovarian cancer syndrome

No single family-history feature establishes HBOC, but certain patterns justify a discussion with an oncologist or genetics professional about hereditary risk assessment and possible testing.[1][5][6]
Examples of personal and family history patterns that may suggest an inherited breast or ovarian cancer predisposition.
Pattern Why it may suggest hereditary risk
Breast cancer at a relatively young age or multiple relatives with breast cancer on the same side of the family Early onset or clustering can suggest an inherited predisposition rather than chance alone.
Epithelial ovarian cancer (including fallopian-tube or primary-peritoneal cancer) in the family.[1][5] These tumours are more likely than some other cancers to be linked with HBOC.
Male breast cancer Strongly associated with BRCA2 and sometimes BRCA1 variants.
Cancer in both breasts, or more than one primary cancer in the same person Multiple independent tumours can reflect an underlying inherited susceptibility.
Breast cancer plus pancreatic cancer or certain prostate cancers in the same family Certain gene variants can increase the risk of combinations of these cancers.
A known pathogenic or likely pathogenic variant in a blood relative Relatives may be offered targeted testing for that specific familial variant.
Very small or poorly documented families, or many relatives who died young Limited information can hide an inherited pattern; personal tumour features become especially important.[1][5]
Features such as triple-negative breast cancer, or a combination of breast cancer with pancreatic or certain prostate cancers, can be especially informative when interpreted alongside pathology reports. It is important to confirm where a cancer started: relatives may use the word ovarian for a cancer that began elsewhere in the abdomen, and a metastatic tumour is not the same as a second primary cancer.
An apparently negative family history does not always remove concern. A family may be small, contain few female relatives, have missing medical information or carry a variant through men who have not developed cancer. Current testing criteria also consider aspects of an individual's own diagnosis, so family history is only one part of the decision.

Family-history assessment and genetic counselling in India

Before testing, a clinician or genetic counsellor commonly builds a family tree covering about three generations. Useful details include each relative's relationship to you, current age or age at death, type of cancer, age at diagnosis, whether the cancer was bilateral or one of several primary cancers, and any available pathology or genetic reports. Information from both sides of the family should be recorded, even when details are incomplete.
When possible, testing may begin with a relative who has had a relevant cancer because their result can be more informative than testing an unaffected relative first. If that person is unavailable or chooses not to be tested, a genetics professional can explain what testing another family member may and may not establish.
Pre-test counselling covers the purpose and scope of testing, possible outcomes, limitations, costs, consent, privacy, emotional effects and potential implications for relatives. Germline testing generally examines DNA from a blood or saliva sample. A variant found only through tumour testing is not automatically confirmed as inherited and may require a separate germline assessment.
Post-test counselling places the laboratory report alongside the family history and explains what is known, what remains uncertain and whether relatives could benefit from targeted assessment. In India, this service may be provided through an oncology team, a clinical genetics service or a trained genetic counsellor. Where local access is limited, tele-genetic counselling may be considered, provided that clinical responsibility, consent, report access and follow-up arrangements are clear.[6]

Choosing between BRCA-only testing and a multigene hereditary cancer panel

BRCA-only testing concentrates on BRCA1 and BRCA2. A clinician may consider it when the personal and family pattern is strongly aligned with BRCA-related disease, when a focused answer is needed, or when the testing strategy has been narrowed by previous results. If a specific familial variant is already known, targeted testing for that variant may be more appropriate than repeating a broad test in every relative.
A multigene panel examines BRCA1, BRCA2 and additional cancer-predisposition genes at the same time. It may be useful when several syndromes could explain the family history, when different tumour types occur in the family, or when earlier BRCA testing was negative but inherited risk remains plausible. Panel testing can identify a clinically relevant variant outside BRCA1 and BRCA2 that a narrower test would miss.
Broader coverage also brings trade-offs. Panels are more likely to identify variants of uncertain significance, and some included genes have less precise risk estimates or limited evidence about how a result should alter care. Cost, laboratory methods and the number and relevance of genes included can vary. More genes do not automatically mean a better test.[4]
The choice should be made with a clinician or qualified genetics professional who can connect the test to a defined clinical question. Useful points to clarify include which genes are included, whether the laboratory assesses both small sequence changes and larger deletions or duplications, how variants are classified, and what post-test support is available.[4]
Comparison of BRCA-only testing and multigene hereditary cancer panel testing.
Aspect BRCA-only testing Multigene panel testing
Genes analysed BRCA1 and BRCA2 (and sometimes a known familial variant only). BRCA1, BRCA2 and multiple additional cancer-predisposition genes chosen by the laboratory.
Typical indications History highly suggestive of BRCA-related disease, or follow-up testing for a known familial BRCA variant. Mixed cancer types, overlapping syndromes, or persistent suspicion of hereditary risk after earlier BRCA-only testing.
Main advantages More focused result, usually fewer uncertain findings, may be simpler to interpret when BRCA is the main concern. Broader search for hereditary causes, potential to detect relevant variants in genes beyond BRCA1 and BRCA2 in a single test.
Limitations and trade-offs Will not detect variants in other genes that might explain the family pattern; may need additional testing later. More likely to identify variants of uncertain significance; some genes have limited data to guide changes in care.[4]
Chance of uncertain results (VUS) Lower than with large panels, but VUS are still possible. Higher than with BRCA-only testing because many more genes are examined.
Cost and logistics Cost and turnaround time vary by laboratory and market; a focused test may reduce report length but is not necessarily less expensive.[4] Cost and turnaround time vary; broader panels generally increase interpretation complexity but are not necessarily more expensive.[4]

Understanding hereditary cancer test results: positive, negative and uncertain

A positive result usually means that the laboratory identified a pathogenic or likely pathogenic germline variant associated with inherited cancer predisposition. It may help explain the cancer pattern in a family and make targeted testing possible for relatives. It does not mean that an unaffected carrier currently has cancer or will definitely develop it, and the implications depend on the particular gene and variant.[5]
A true negative is possible when a pathogenic familial variant has already been identified and another relative tests negative for that exact variant. This generally shows that the relative did not inherit that specific familial predisposition, although their ordinary health risks and any unrelated family factors still need appropriate clinical consideration.
An uninformative negative has a different meaning. If no familial variant is known, a negative BRCA1 and BRCA2 result shows only that the test did not identify a reportable variant in those genes using the method performed. Another gene, a variant not detected by that method, an incompletely understood genetic factor or a non-genetic explanation may still account for the family pattern. A negative BRCA result therefore does not automatically exclude hereditary cancer risk or erase the relevance of a strongly suggestive family history.[5]
A variant of uncertain significance, or VUS, is a DNA change for which available evidence cannot establish whether it is harmful or harmless. It should not be treated as a positive result, and major clinical decisions should not be based on the VUS alone. Classification can change as evidence develops, so the laboratory or care team may later provide an updated interpretation.[7]

What hereditary cancer results can mean for you and your family

A clinically significant finding can inform future discussions about cancer surveillance, risk-reduction choices and the relevance of particular findings to an existing cancer. These decisions are gene-specific and must take account of age, health, personal preferences and the strength of the evidence. A laboratory result by itself is not a complete care plan.
Once a familial pathogenic variant is known, adult blood relatives may be offered cascade testing for that specific variant. This is more focused than repeating a broad panel and separates relatives who inherited the familial variant from those who did not. Testing is voluntary, and sharing information can be emotionally difficult, particularly when family relationships or communication are strained.[3][5][6]
Some carriers also choose to discuss reproductive implications with a genetics or reproductive specialist. The relevance and timing of that conversation depend on personal circumstances and the gene involved. It should be approached as informed counselling rather than as an assumption about what an individual or couple ought to do.

Hereditary cancer panel testing options in India

Verified Oncquest offering facts

1

Available offering

Oncquest Laboratories lists a diagnostic service named OncqHereditary Cancer Panel in its online test catalogue.

Why it matters for you

The current Oncquest catalogue confirms a dedicated hereditary cancer panel entry.

2

Current listed specifications

Oncquest's current catalogue identifies the OncqHereditary Cancer Panel as test SMO10689 using NGS on 2 mL whole blood in EDTA, with a broad Components gene list and a listed 25-day turnaround time. Its linked sample report provides panel coverage and describes SNV and CNV analysis; these operational and scope details should be reconfirmed when ordering.

Why it matters for you

The listed method, specimen, gene content and turnaround time should be reconfirmed when ordering.

3

Details to confirm

The current catalogue and sample report both publish broad gene content, but their lists may not be identical. The report describes SNV and CNV analysis while also stating that the methodology does not detect large deletions/duplications and recommending BRCA1/2 MLPA. Confirm the exact ordered panel, validated variant classes, deletion/duplication method, analytical performance and reanalysis or notification policy with the laboratory.

Why it matters for you

The catalogue and report should be reconciled before relying on the exact panel or deletion/duplication scope.

When a clinician concludes that broader testing is appropriate, a multigene hereditary cancer panel can examine BRCA1, BRCA2 and other selected predisposition genes in one analysis. Broader is not automatically better: the panel’s gene content, validated variant classes and reporting policy must match the personal and family-history question.[4]
The Oncquest Laboratories Hereditary Cancer Panel is one example that an oncologist or genetic counsellor may consider in this setting. You can review the test-information page for current catalogue details. At this review, the catalogue identifies test SMO10689 as NGS on 2 mL whole blood in EDTA, lists a broad Components gene set and a 25-day turnaround time. The sample report describes SNV and CNV analysis but also notes CNV limitations, says the methodology does not detect large deletions/duplications and recommends BRCA1/2 MLPA. Because the catalogue and report gene lists may differ, confirm the exact ordered panel, validated variant classes, analytical performance and reanalysis policy, and keep interpretation clinician-guided.[4][8][9]

Safety, limitations and questions to discuss with your care team

Bring a written family history, copies of pathology or genetic reports if available, and the name of any relative known to carry a variant. You can ask which diagnosis or family pattern is driving the recommendation, whether an affected relative would be more informative to test first, and why BRCA-only testing, targeted testing or a multigene panel is being considered.
Before giving consent, ask which genes and variant types the test covers, which sample is required, whether findings unrelated to the original question could be reported, how your genetic data will be stored or shared, and who will interpret the result. It is also reasonable to discuss the total cost pathway, including counselling, confirmatory work where relevant and family testing, rather than considering the laboratory test alone.[4][6]
Risk estimates and testing criteria can change as evidence develops, and much of the available risk data comes from populations outside India. Ask how well the evidence applies to your family and whether the laboratory follows recognised quality and variant-classification standards. Legal and insurance protections differ by country, so protections described in resources from other countries should not be assumed to apply in India.[6]
FAQs

Yes, in some circumstances. Men can inherit and pass on BRCA1, BRCA2 and other relevant variants, and certain variants are associated with male breast, prostate, pancreatic or other cancer risks. Assessment may be appropriate when a man has a relevant personal history, a known familial variant or a suggestive cancer pattern on either side of the family.

Germline testing commonly uses blood or saliva because it is intended to identify variants present from birth throughout the body. Tumour testing examines changes in cancer cells and may detect both acquired and potentially inherited variants. A tumour finding is not automatically proof of an inherited variant, so separate germline testing may be needed.

For BRCA1/2, professional groups generally do not recommend predictive testing before age 18 because BRCA-specific risk management does not begin in childhood. Broader-panel decisions can differ when a genuine childhood-onset syndrome is suspected and require specialist counselling.[3][5]

A genetic result can raise sensitive questions about privacy, disclosure, insurance and family communication. Laws, policies and consent practices can change, and protections described for other countries should not be assumed to apply in India. Before testing, ask who can access the result, how it will be stored or shared, and where to obtain current India-specific professional or legal guidance.[6]

A clinician may reconsider testing when an older test examined only part of BRCA1 or BRCA2, did not assess certain variant types, or did not include genes now relevant to the family pattern. Reassessment may also be useful after a new familial variant is found or when a laboratory reclassifies an earlier variant of uncertain significance. Repeating a test is not automatically necessary; the original report and methods should be reviewed first.

Sources
  1. Genetics of Breast and Gynecologic Cancers (PDQ) – Health Professional Version - National Cancer Institute (NCI)
  2. BRCA1 and BRCA2 (PDQ) – Health Professional Version - National Cancer Institute (NCI)
  3. BRCA1- and BRCA2-Associated Hereditary Breast and Ovarian Cancer - GeneReviews® / NCBI Bookshelf
  4. Selection of Germline Genetic Testing Panels in Patients With Cancer: ASCO Guideline - Journal of Clinical Oncology / American Society of Clinical Oncology (ASCO)
  5. Genetic Testing for Hereditary Breast and Ovarian Cancer - Centers for Disease Control and Prevention (CDC)
  6. Genetic Counselling, Testing, and Management of Hereditary Breast and Ovarian Cancer Syndrome in India: Updated Expert Consensus Recommendations from ISMPO - Indian Journal of Medical and Paediatric Oncology / Indian Society of Medical and Paediatric Oncology (ISMPO)
  7. EMQN Best Practice Guidelines for Genetic Testing in Hereditary Breast and Ovarian Cancer - European Journal of Human Genetics / European Molecular Genetics Quality Network (EMQN)
  8. OncqHereditary Cancer Panel – Test Information - Oncquest Laboratories Ltd.
  9. OncqHereditary Cancer Panel (SMO10689) Sample Report - Oncquest Laboratories

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Updated At Oct 20, 2026

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