The short answer
Many cancer predisposition variants, including BRCA1 and BRCA2, pass with a 50% chance to each child. Inheriting one raises risk without guaranteeing cancer. A genetic counselor can talk through the risk of passing a variant on, and family-planning questions, with you.
For BRCA1 and BRCA2, each child of a carrier has a 50% chance of inheriting the variant. The chance applies separately to each child; it is not a quota across siblings.
Inheriting a variant raises risk; it does not guarantee cancer, and risk levels differ between genes.
Professional groups do not recommend genetic testing of children under 18 for BRCA1 and BRCA2 changes, because no specific risk-reduction steps exist for children and they rarely develop BRCA-related cancers.
Genetic counseling should cover the risk of passing a variant to children. Ask your counselor about family-planning options.
On this page
Choose how you want to read this
The whole article, with every detail and caution.
This page is for people who carry an inherited gene change that raises cancer risk and worry about passing it to their children. It covers what the odds mean, reproductive options, testing children, and how to talk with them.
What the inheritance numbers mean
For BRCA1 and BRCA2, NCI says each child of a carrier has a 50% likelihood of inheriting the same variant. Many other cancer predisposition variants are passed on in a similar way. The chance applies separately to each child. It is not a quota. Three children can all inherit it, or none can.
Two things often get merged in the middle of the night, and they are worth separating.
Inheriting a variant is not the same as developing cancer. A variant raises risk. It does not schedule an event. Risks vary by gene. Take BRCA1 and BRCA2, where more than 60% of women who carry a harmful variant develop breast cancer. Ovarian cancer risk there runs 39% to 58% for BRCA1 and 13% to 29% for BRCA2. Meaningful, but not certain.
A child who inherits it also inherits the knowledge. They would grow up knowing, and could have screening and prevention planned with their doctors.
Family-planning questions
If you are planning a family, or already have children, a genetic counselor can help. NCI says genetic counseling should include a talk about the risk of passing a variant to children. Ask what choices exist for your gene, and ask the counselor to describe each one without steering you toward any. Options differ in cost, insurance coverage and how well they work, so ask for those details for each one you consider.
Testing children
For BRCA1 and BRCA2, professional groups do not recommend genetic testing for children under 18. No specific risk-reduction steps exist for children, and they rarely develop BRCA-related cancers.
Other genes can be different. Some syndromes involve cancers in childhood. Your genetic counselor can tell you which category your family's gene falls into.
Telling children who are already here
There is no single right age. One approach is to tell a little at a time. Start with a simple, calm version: there is something that runs in our family, and doctors know how to watch for it. Add more detail as your child is ready. A genetic counselor or a therapist who knows hereditary conditions can help you plan the words.
What the fear usually is underneath
The fear of passing something on is rarely about statistics. It is usually a version of not wanting your child to go through what you or your parents went through.
That is worth saying out loud to someone. It could be a genetic counselor, a therapist familiar with hereditary conditions, or a peer support group for your specific syndrome. It does not have to be resolved before you make decisions. And it should not be the only voice in the room when you do.
You did not choose your genome, and you did not design the inheritance. What you can choose is what your family knows and what they are able to do about it.
Sources
Common questions
If I have three children, does that mean one and a half will inherit it?
No. For BRCA1 and BRCA2, NCI describes a 50% likelihood for each child. The chance applies separately to each child. All three could inherit it, or none could. It works like a coin toss each time, not like dividing a fixed amount.
Should I have my children tested now?
For BRCA1 and BRCA2, professional groups do not recommend testing children under 18. No specific risk-reduction steps exist for children, and they rarely develop BRCA-related cancers. Other genes can differ. Your genetic counselor can say what applies to your family's gene.
When should I tell my children?
There is no single right age. Many parents start with a simple, calm version and add detail as the child grows. Your genetic counselor or a therapist who knows hereditary conditions can help you plan the words.
Is it selfish to have biological children knowing I carry a variant?
That is a values question rather than a medical one, and reasonable people answer it differently. A genetic counselor can go over the risk of passing a variant on and the choices open to you, without telling you what to do.
Questions to ask your doctor
Being prepared helps you get the most out of your appointments. Save or print these questions.
Tap a question to save it to your list (kept on this device).
Talk with a trained specialist or navigator
Cancer Explained provides educational guidance, but does not replace trained specialists, social workers, or your medical team.
Talk to a trained cancer information specialist
Free, confidential assistance from NCI Cancer Information Service via phone, chat, or email.
Contact your oncology team
Locate after-hours contact numbers, portal messages, or urgent triage phone lines.
Find a patient navigator
Get one-on-one help with appointments, logistics, translation, and care coordination.
Find a genetic counselor
Discuss inherited mutation risk, family history, and genetic testing options.
Find an oncology social worker
Access emotional counseling, family support groups, and mental health resources.
Find a financial navigator
Locate copay assistance foundations, grant programs, and lodging/travel support.
Find a clinical-trial specialist
Search matching studies and speak with NCI trial information specialists.
Get urgent help
Fever of 100.4°F (38°C) or higher during chemo, severe pain, or trouble breathing: call your cancer care team right away, day or night. Call 911 for an emergency.
Know someone who needs this?
Plenty of people are looking for something like this and do not know where to start. If this would help a friend or someone you love, send it on — we have written an opening line so you do not have to stare at an empty message. You can change every word of it.
Your message is written and sent in your own email or messaging app — we never see who you send it to, and nothing is added to any list.
Plain-language explanation of the published sources cited on this page. AI-assisted, source-checked, not clinician-reviewed.
Written by: Cancer ExplainedSources last checked: 2026-10-02 what this meansLast updated: 2026-10-02Next planned review: 2027-07-30
Review details and limits
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status — Source checked. This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
General education — varies by person. Answers genuinely differ between people. This page explains what commonly varies and points you to your care team for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Words to know
Tap any term to see what it means.
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Read more about our editorial process, our use of AI, and our corrections policy.
Spotted a problem? Report an error — a factual mistake, broken or outdated source, confusing wording, or anything that seems unsafe. Please do not include names, medical record numbers, dates of birth, addresses, or other identifying medical information in your report.
After using this page, do you understand what to do next?
Anonymous — we only record the answer, never who gave it.