Breast Cancer Risk Factors: Inherited Gene Mutations

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This section provides information on high-risk inherited gene mutations, and how they impact breast cancer risk.

Learn about other risk factors for breast cancer.

Genes and inherited gene mutations

What are genes?

Every cell in your body has genes. Genes contain the genetic code (blueprints) for your body.

For example, genes contain the information that determines the color of your eyes. They also contain information that affects how the cells in your body grow, divide and die.

The information in your genes is inherited (passed on from your mother and your father). And you can pass this information on to your daughters and your sons.

What are inherited gene mutations?

Some changes in the genetic code that affect the function of the gene are called mutations. Mutations are rare.

Just as with other information in genes, mutations can be inherited (passed on from a parent to a child). Inherited gene mutations may also be called germline mutations.

Though gene mutations can be passed down from parent to child, this doesn’t mean if one of your parents has a mutation you will have the mutation. You get one copy of each gene from your mother and one copy from your father.

For example, your mother has two BRCA1 genes. If one of your mother’s BRCA1 genes has a mutation (and her other BRCA1 gene doesn’t have a mutation), there’s a 50% chance you’ll inherit the mutation and a 50% chance you won’t. You get one of your two BRCA1 genes from your mother and it’s random which copy you get.

Inherited gene mutations and health

Many inherited gene mutations have little or no effect on health (good or bad). Others can increase the risk of certain diseases, including breast cancer.

Inherited gene mutations and breast cancer risk

Inherited gene mutations known to increase the risk of breast cancer are rare in the general population.

In the U.S., 5%-10% of breast cancers are related to a known inherited gene mutation [6,38].

BRCA1 and BRCA2 (BReast CAncer genes 1 and 2) are the most well-known genes linked to breast cancer risk.

Everyone has BRCA1 and BRCA2 (BRCA1/2) genes. Some people have an inherited mutation in one or both of these genes that increases the risk of breast cancer.

Inherited mutations in the following genes also increase the risk of breast cancer [39]:

ATM
BARD1
CDH1
CHEK2
NF1
PALB2
PTEN
RAD51C
RAD51D
STK11
TP53

Other genes are under study and may also play a role in breast cancer.

BRCA1/2 and other inherited gene mutations can be passed to you from either parent and can affect the risk of cancers in both women and men.

Some inherited gene mutations slightly increase breast cancer risk, while others (such as BRCA1/2 mutations) greatly increase risk.

BRCA1 and BRCA2 inherited gene mutations

Like other inherited gene mutations, BRCA1 and BRCA2 (BRCA1/2) gene mutations are rare in the general population. In the U.S., about 1 in 400 to 1 in 800 people have a BRCA1/2 mutation [38].

People of all races and ethnicities can have BRCA1/2 inherited gene mutations. However, the proportion of people with a BRCA1/2 gene mutation varies by ethnic group. Among Ashkenazi Jewish men and women, about 1 in 40 have a BRCA1/2 mutation [38].

Learn more about BRCA1/2 inherited gene mutations in women.

Learn more about BRCA1/2 inherited gene mutations in men.

BRCA1 and BRCA2 inherited gene mutations and cancer in women

Breast cancer

Women with a BRCA1 or BRCA2 (BRCA1/2) inherited gene mutation have an increased risk of breast cancer [33-39].

The lifetime risk of developing breast cancer is [39-40]:

More than 60% for women with a BRCA1/2 inherited gene mutation
13% for women in the general population

This means over a lifetime:

In a group of 100 women with a BRCA1/2 gene mutation, more than 60 will get breast cancer
In a group of 100 women without a BRCA1/2 gene mutation, about 13 will get breast cancer

These numbers are averages. The risk of breast cancer for any one woman with a BRCA1/2 gene mutation may fall outside this range.

Note these risks are not 100%. Many women with a BRCA1/2 gene mutation will never have breast cancer [33-35]. A combination of factors likely causes breast cancer. So, some women with a BRCA1/2 mutation will get breast cancer and many will not.

Ovarian cancer and other cancers

BRCA1 and BRCA2 inherited gene mutations increase a woman’s risk of ovarian cancer, pancreatic cancer and melanoma (BRCA2 mutations only) [36,38-39].

BRCA1/2 gene mutations may also increase the risk of other cancers [38]. However, data are limited, and these topics are still under study.

Learn more about BRCA1/2 inherited gene mutations in women.

Learn about risk-reducing options for women at higher risk.

Learn about genetic testing.

For a summary of research studies on BRCA1 and BRCA2 inherited gene mutations and cancer, visit the Breast Cancer Research Studies section.

BRCA1 and BRCA2 inherited gene mutations and cancer in men

Men can also have BRCA1 and BRCA2 (BRCA1/2) inherited gene mutations and may pass them on to their daughters and sons.

Men with a BRCA2 gene mutation, and to a lesser degree, men with a BRCA1 gene mutation, have an increased risk of breast cancer [33,35,38-39,192-194].

For men, BRCA1/2 mutations also increase the risk of prostate cancer, pancreatic cancer and melanoma (BRCA2 mutations) [33,38-39,194].

Learn more about BRCA1/2 inherited gene mutations in men.

Learn more about breast cancer in men.

Learn about cancer screening for men with a BRCA1/2 inherited gene mutation.

Learn about genetic testing.

For a summary of research studies on BRCA1 and BRCA2 inherited gene mutations and cancer, visit the Breast Cancer Research Studies section.

Other inherited gene mutations

In addition to BRCA1 and BRCA2 (BRCA1/2) inherited gene mutations, other inherited gene mutations increase the risk of breast cancer. Some of these gene mutations are linked to a high risk of breast cancer, similar to BRCA1/2 mutations. Some also increase the risk of other cancers.

High-risk inherited gene mutations increase the lifetime risk of breast cancer to 20% or higher. (The lifetime risk of breast cancer for the average woman is about 13%.) In general, having a mutation in any of these genes leads to special breast cancer screening recommendations.

Compared to BRCA1/2 gene mutations, other high-risk inherited gene mutations are less common. Some of these mutations have only recently been shown to increase the risk of breast cancer. So, there’s still much to learn about them and our understanding of their related cancer risks may change over time.

The table below provides a summary of high-risk inherited gene mutations.

Gene (in alphabetical order)	Lifetime risk of breast cancer	Additional cancers with increased risk
ATM	20%-25%	Pancreatic cancer, possibly colorectal cancer, possibly ovarian cancer, possibly prostate cancer
BARD1	20%-30%	None known
BRCA1	60%-70%	Ovarian cancer, pancreatic cancer, prostate cancer, possibly uterine cancer (serous type)
BRCA2	55%-70%	Melanoma, ovarian cancer, pancreatic cancer, prostate cancer
CDH1	40%-55%	Stomach cancer (diffuse type)
CHEK2	20%-30%	Possibly prostate cancer
NF1	20%-40%	Brain and spinal tumors, gastrointestinal stromal tumors, other rare tumors
PALB2	30%-50%	Ovarian cancer, pancreatic cancer
PTEN	More than 60%	Colon cancer, endometrial cancer, thyroid cancer, possibly kidney cancer
RAD51C	20%	Ovarian cancer
RAD51D	20%	Ovarian cancer
STK11	30%-55%	Endometrial cancer, ovarian cancer (sex cord type), pancreatic cancer
TP53	More than 60%	Adrenocortical carcinoma, brain tumors, colon cancer, leukemia, melanoma, pancreatic cancer, prostate cancer, sarcomas (soft tissue and bone cancers)
Adapted from National Comprehensive Cancer Network (NCCN), 2024 [39].

Some gene mutations are related to certain breast cancers. For example, women with a BRCA1 gene mutation tend to get breast cancers that are triple negative [38,195-196]. And CDH1 gene mutations are related more often to invasive lobular breast cancers than invasive ductal breast cancers [197].

Genetic testing for multiple high-risk inherited gene mutations

It’s now common for genetic testing to check for multiple high-risk inherited gene mutations, including BRCA1 and BRCA2 (BRCA1/2) mutations. This is called hereditary cancer panel testing or multi-gene testing.

Because panel testing is still fairly new, the specific set of genes checked for mutations can vary from test to test.

Panel testing is only recommended for some people.

As with any genetic testing, panel testing should only be done in a medical setting after a detailed discussion of the risks and benefits with a genetic counselor or a trained doctor or nurse [39]. These trained health care providers can also help determine the best test (and lab), given the pattern of cancer in your family.

Most insurance plans cover the cost of BRCA1/2 testing if you meet the criteria for testing. Coverage of hereditary cancer panel testing varies from plan to plan. A genetic counselor can help you determine if your insurance will cover BRCA1/2 or panel testing.

Learn more about hereditary cancer panel testing.

Learn more about genetic testing costs.

Breast cancer screening

Women with a BRCA1/2 inherited gene mutation have special breast cancer screening guidelines.
Men with a BRCA1/2 inherited gene mutation have special cancer screening guidelines.
Transgender people with a BRCA1/2 inherited gene mutation have special cancer screening guidelines.

Guidelines for people with other high-risk gene mutations are less clear. As more is learned about these mutations, guidelines can become more personalized.

Learn more about special breast cancer guidelines for women with an inherited mutation in an ATM, BARD1, CDH1, CHEK2, NF1, PALB2, PTEN, RAD51C, RAD51D or TP53 gene.

Breast cancer risk reduction

There are special breast cancer risk reduction guidelines for women with a BRCA1/2 inherited gene mutation.

Guidelines for women with other high-risk gene mutations are less clear. As more is learned about these mutations, guidelines can become more personalized.

Learn more about risk reduction options for women at higher risk of breast cancer.

Talking about family health history with your health care provider

Your family history of breast cancer and other health conditions is important to discuss with your health care provider. This information helps them understand your risk of breast cancer.

My Family Health History Tool

My Family Health History tool is a web-based tool that makes it easy for you to record and organize your family health history. It can help you gather information that’s useful as you talk with your family members, doctor or genetic counselor.

Support for people with inherited gene mutations

Some support groups are tailored to people with BRCA1, BRCA2 or other high-risk inherited gene mutations and those with breast cancers related to inherited gene mutations.

Our Support section has a list of resources to help find local and online support groups. For example, FORCE is an organization that provides virtual support groups, telephone support, education and resources for individuals and caregivers affected by hereditary breast, ovarian and other cancers.

Sharsheret offers virtual programs and peer for Jewish women affected by hereditary breast and/or ovarian cancer.

Susan G. Komen^® Support Resources

Do you need more information about breast cancer risk factors? We’re here for you. The Komen Patient Care Center is your trusted, go-to source for timely, accurate breast health and breast cancer information, services and resources. Our navigators offer free, personalized support for you and your loved ones including education, emotional support, financial assistance, help accessing care and more. Get connected to a Komen navigator by contacting the Breast Care Helpline at 1-877-465-6636 or email helpline@komen.org to get started. All calls are answered Monday through Thursday, 9 a.m. to 7 p.m. ET and Friday, 9 a.m. to 6 p.m. ET. Se habla español.
The Komen Breast Cancer and Komen Metastatic (Stage IV) Breast Cancer Facebook groups are places where those with breast cancer and their family and friends can talk with others for friendship and support.
Our fact sheets, booklets and other education materials offer additional information.

Finding clinical trials for people with inherited gene mutations

Susan G. Komen^® Patient Care Center

If you or a loved one needs information or resources about clinical trials, the Patient Care Center can help. Contact the Komen Breast Care Helpline at 1-877-465-6636 or email clinicaltrialinfo@komen.org.

Se habla español.

BreastCancerTrials.org in collaboration with Komen offers a custom matching service to help find breast cancer risk reduction clinical trials.

You can also visit the National Institutes of Health’s website to find clinical trials.

Learn more about clinical trials.

1. Know your risk

Talk with both sides of your family to learn about your family health history.
Talk with a health care provider about your risk of breast cancer.

2. Get screened

Talk with a health care provider about which screening tests are right for you if you’re at higher risk.
Have a mammogram every year starting at age 40 if you’re at average risk.*
Have a clinical breast exam at least every 3 years starting at age 25, and every year starting at age 40.*

* Per National Comprehensive Cancer Network Guidelines

3. Know what is normal for you

See a health care provider if you notice any of these breast changes: