BRCA1 and BRCA2 Genes: What You Need to Know

BRCA1 and BRCA2 are among the most widely recognized genes associated with hereditary cancer risk. These genes produce proteins that help repair damaged DNA, acting as tumor suppressors. When either gene carries a harmful mutation, the body’s ability to repair DNA damage is compromised, which can lead to an accumulation of genetic errors and, in some cases, cancer.

What Do BRCA1 and BRCA2 Do?

Everyone has two copies of both the BRCA1 and BRCA2 genes — one inherited from each parent. Under normal circumstances, these genes help maintain genomic stability by repairing double-strand DNA breaks through a process called homologous recombination.

When a person inherits a pathogenic variant in one copy of either gene, their cells have a reduced capacity for DNA repair. Over time, this may allow additional mutations to accumulate, potentially leading to uncontrolled cell growth.

Cancer Risks Associated with BRCA Mutations

Carrying a BRCA1 or BRCA2 mutation does not mean a person will definitely develop cancer. However, the lifetime risk is significantly elevated compared to the general population:

• Breast cancer: Women with BRCA1 or BRCA2 mutations may have a 45 to 72 percent lifetime risk, compared to about 13 percent in the general population.
• Ovarian cancer: Risk may range from 10 to 44 percent, compared to about 1.2 percent in the general population.
• Male breast cancer: Men with BRCA2 mutations have an increased risk, though the absolute risk remains relatively low.
• Prostate cancer: BRCA2 mutations in particular are associated with increased risk and potentially more aggressive forms.
• Pancreatic cancer: Both BRCA1 and BRCA2 mutations may modestly increase pancreatic cancer risk.

Beyond BRCA: Other Genes to Know

While BRCA1 and BRCA2 are the most well-known, they are not the only genes linked to hereditary cancer. Genes such as PALB2, ATM, CHEK2, and RAD51C/D are also associated with increased breast cancer risk, though often at moderate rather than high levels. Multi-gene panel testing can evaluate many of these genes simultaneously.

Who Should Consider BRCA Testing

BRCA testing may be recommended for individuals whose personal or family history suggests a hereditary pattern. Common indicators include:

• Breast cancer diagnosed before age 50
• Ovarian, fallopian tube, or primary peritoneal cancer at any age
• Triple-negative breast cancer diagnosed before age 60
• Male breast cancer
• Multiple breast cancers in the same person or close relatives
• Ashkenazi Jewish, Icelandic, or other ancestry with higher prevalence of founder mutations
• A known BRCA mutation in the family

Management Options After a Positive Result

A positive BRCA result opens up several evidence-based management strategies, which should always be discussed with your healthcare team:

• Enhanced surveillance with more frequent mammograms and breast MRI
• Risk-reducing medications that may lower breast cancer risk
• Preventive surgical options such as mastectomy or oophorectomy, which some individuals choose after thorough counseling
• Cascade testing for at-risk family members — learn more in our article on understanding your results

The Importance of Genetic Counseling

BRCA test results should always be interpreted in the context of your complete personal and family history. A licensed genetic counselor can help you understand the nuances of your result, discuss the implications for cancer risk management, and guide conversations with family members who may also benefit from testing.