Most ovarian cancers are not inherited, but genetics play a larger role here than in many other cancers. Roughly 10% to 15% of ovarian cancers are hereditary, meaning they’re driven by a gene mutation passed down from a parent. The remaining 85% to 90% arise from genetic changes that happen over a person’s lifetime rather than being inherited at birth.
That 10% to 15% figure is notably higher than what you see with breast cancer, where only 5% to 10% of cases are hereditary. So while most people diagnosed with ovarian cancer don’t carry an inherited mutation, the odds of a genetic link are real enough that understanding your family history matters.
BRCA1 and BRCA2: The Biggest Genetic Risk Factors
The two genes most strongly tied to hereditary ovarian cancer are BRCA1 and BRCA2. These genes normally help your cells repair damaged DNA. When one of them carries a mutation, that repair system doesn’t work properly, and cells are more likely to become cancerous. About 10% of all ovarian cancers result from mutations in these two genes alone.
The lifetime risk numbers are striking. A woman with a BRCA1 mutation has roughly a 44% chance of developing ovarian cancer by age 80. For BRCA2 carriers, the lifetime risk is about 17%. Compare that to the general population’s lifetime risk of around 1.4%, and you can see why these mutations get so much attention. BRCA1 tends to cause ovarian cancer at younger ages than BRCA2, often before menopause.
Both mutations are inherited in what’s called an autosomal dominant pattern. That means you only need one copy of the mutated gene (from either parent) to have the increased risk. If a parent carries a BRCA mutation, each child has a 50% chance of inheriting it. Men can carry and pass on these mutations too, even though they don’t have ovaries.
Lynch Syndrome and Other Genetic Links
BRCA mutations get the most headlines, but they aren’t the only inherited cause. Lynch syndrome accounts for 10% to 15% of hereditary ovarian cancers. This condition involves mutations in genes responsible for fixing small errors that happen when your DNA copies itself. When those repair genes don’t function correctly, errors accumulate, and cancer risk rises across several organs, including the ovaries, uterus, and colon.
Women with Lynch syndrome have about an 8% lifetime risk of ovarian cancer, roughly six times higher than the general population. Lynch syndrome is also more common than many people realize, affecting somewhere between 1 in 37 and 1 in 111 people. It often goes undiagnosed because families may attribute their cancer history to bad luck rather than a shared genetic cause.
A handful of other gene mutations, including those in RAD51C, RAD51D, and BRIP1, also modestly increase ovarian cancer risk, though each one is rarer and carries a lower risk than BRCA1 or BRCA2.
Who Is More Likely to Carry a Mutation
Certain populations have higher rates of BRCA mutations. People of Ashkenazi Jewish descent carry BRCA mutations at a rate of about 1 in 40, compared to roughly 1 in 300 to 1 in 500 in the general population. This is because three specific BRCA mutations became common in the Ashkenazi Jewish population through what geneticists call a “founder effect,” where a small ancestral group happened to carry these variants, and they persisted as the population grew.
Beyond ethnicity, your family history is the strongest signal. Red flags include two or more close relatives with ovarian cancer, a relative diagnosed with ovarian cancer before age 50, a family history that includes both breast and ovarian cancer, or a male relative with breast cancer (which also links to BRCA mutations). Cancer on your father’s side counts just as much as your mother’s side, since either parent can pass on the mutation.
How Genetic Testing Works
Genetic testing for ovarian cancer risk is straightforward. Blood is the most common sample source, though saliva has become a convenient alternative that many labs now accept. The test analyzes your DNA for known mutations in BRCA1, BRCA2, Lynch syndrome genes, and sometimes a broader panel of cancer-related genes.
Results typically fall into three categories: positive (a known harmful mutation was found), negative (no mutation detected), or a “variant of uncertain significance,” meaning a change was found but scientists don’t yet know whether it increases risk. That last result can be frustrating, but it doesn’t mean something is wrong. It simply means more data is needed.
Testing is most informative when it starts with a family member who has already been diagnosed with cancer. If their test identifies a specific mutation, other relatives can then be tested for that exact variant. If no living affected relative is available, you can still be tested, but a negative result is harder to interpret since your family’s cancer could be driven by a mutation the test doesn’t cover.
What a Positive Result Means in Practice
Learning you carry a BRCA or Lynch syndrome mutation doesn’t mean you will get ovarian cancer. It means your risk is substantially higher than average, and that opens up options for managing that risk proactively.
The most effective risk-reduction strategy for high-risk carriers is preventive surgery to remove the ovaries and fallopian tubes. This procedure reduces ovarian cancer risk by roughly 80% to 90% in BRCA carriers. For BRCA1 carriers, doctors generally recommend considering this surgery between ages 35 and 40, after completing childbearing. BRCA2 carriers, whose ovarian cancer tends to develop later, may have the option to wait until their early to mid-40s. For Lynch syndrome carriers, the timing depends on individual risk factors and family history.
Screening for ovarian cancer in high-risk women is less reliable than screening for other cancers. Transvaginal ultrasound and a blood marker called CA-125 can be used for monitoring, but neither catches ovarian cancer early enough to significantly improve survival on its own. This is part of why preventive surgery, rather than surveillance alone, is the primary recommendation for mutation carriers.
When Family History Matters Without a Known Mutation
Not every family pattern of ovarian cancer traces back to an identifiable gene mutation. Some families have a clustering of cases that genetic testing can’t fully explain. This could reflect mutations in genes that haven’t been discovered yet, combinations of smaller genetic effects, shared environmental exposures, or simply chance.
Even without a confirmed mutation, a strong family history of ovarian cancer still raises your personal risk above the general population’s baseline. If you have a first-degree relative (mother, sister, daughter) who had ovarian cancer, your own risk roughly triples compared to someone with no family history, regardless of genetic test results. That family context is worth sharing with your doctor so that appropriate monitoring or risk-reduction conversations can happen early.