What is hereditary cancer?
A hereditary cancer syndrome occurs when a disease-associated germline variant is present from conception and can be passed through a family. Examples include syndromes involving BRCA1, BRCA2 and other cancer-predisposition genes.
Frequently asked questions about hereditary cancer
Key points
- Hereditary cancer is about inherited susceptibility, not certainty.
- Family history can guide testing.
- Results may affect relatives as well as the person tested.
Most cancers are not inherited as a single-gene syndrome
Cancer develops through genetic changes in cells, but only a minority of cancers are caused mainly by an inherited pathogenic variant that substantially increases cancer susceptibility.
Clues in a family history
Features that can raise suspicion include cancer at unusually young ages, multiple relatives with related cancers, more than one primary cancer in one person, rare cancer types, bilateral disease in paired organs, or a known familial pathogenic variant.
What germline testing can show
Testing may identify a pathogenic/likely pathogenic variant, a variant of uncertain significance, or no relevant pathogenic variant in the genes analysed. A negative result does not always eliminate hereditary risk.
Why counselling matters
The implications can affect cancer screening, risk-reducing options, treatment and biological relatives. Pre- and post-test counselling helps patients understand possible outcomes and limitations.
Family members
When a clinically important inherited variant is found, targeted testing may be offered to appropriate relatives so they can understand whether they carry the familial change.
This resource is for general education and does not replace individual medical, genetic, legal or laboratory advice.
Clinical reference sources
- ACOG \u2014 Current Guidance: Cell-Free DNA/NIPT
- ACOG \u2014 Prenatal Genetic Screening Tests
- ASRM \u2014 The Use of PGT-A: Committee Opinion (2024)
- ASRM \u2014 Indications and Management of PGT-M
- NCI \u2014 Genetic Testing Fact Sheet
- NCI \u2014 BRCA Gene Changes: Cancer Risk and Genetic Testing
- AABB \u2014 DNA Relationship Testing FAQs
- AABB \u2014 Standards for Relationship Testing Laboratories
Concerned about your family cancer history?
Speak with our genetics team for personalized counselling.