01 / 08
What are BRCA1 and BRCA2?
BRCA1 and BRCA2 are genes—not diseases. Everyone has both. They provide instructions for proteins that help repair damaged DNA and suppress uncontrolled cell growth.
A harmful change may be called a mutation, although clinical laboratories generally use pathogenic variant or likely pathogenic variant. Only some people inherit one of these variants; having one raises susceptibility to certain cancers but does not mean cancer is present or inevitable. [1,5,6]
02 / 08
What cancer risks are linked to a BRCA variant?
The figures below are cumulative risk estimates for people with pathogenic variants. Ranges vary by study population, family history, age, and source; they are not an individual prediction. [1,8]
| Cancer risk | BRCA1 | BRCA2 | General population |
|---|---|---|---|
| Female breast, lifetime | 55–72% [1] | 45–69% [1] | ~13% [1] |
| Ovarian, lifetime | 39–58% [1] | 13–29% [1] | 1.1–2% [1] |
| Prostate, by age 80 | 7–26% [1] | 19–61% [1] | ~10.6–16% [1] |
| Pancreatic, lifetime | Up to 5% [1] | 5–10% [1] | ~1–1.7% [1] |
Female breast and ovarian estimates are lifetime risks; prostate estimates are through age 80. The exact source denominator and age horizon matter when comparing figures.
03 / 08
How common are BRCA variants?
Three founder variants—BRCA1 c.68_69delAG (historically 185delAG), BRCA1 c.5266dupC, and BRCA2 c.5946delT (historically 6174delT)—account for many hereditary BRCA findings in this population. Ancestry can inform testing, but founder-only testing can miss other pathogenic variants. [8,10]
04 / 08
How are BRCA1 and BRCA2 inherited?
Hereditary cancer susceptibility from one pathogenic BRCA1 or BRCA2 variant follows an autosomal dominant pattern. Each child of a carrier has a 50% chance of inheriting the variant, independently for each pregnancy. Both men and women can carry, inherit, and pass on a variant. [1,8]
06 / 08
WGS breadth—and where a focused test can be better
Choose a test around the clinical question. More genomic data is not automatically a more definitive answer.
| Approach | Useful strength | Important limit |
|---|---|---|
| Targeted familial-variant test | Directly asks whether you inherited the exact variant already found in a relative. | Does not look broadly for unrelated risks. |
| Hereditary cancer panel | Focused clinical analysis of BRCA1/2 and other relevant cancer genes. | Scope varies by laboratory and panel. |
| Clinical whole genome sequencing | Broad data collection across the genome can support analysis beyond one cancer question. | Validated coverage, reportable genes, variant classes, confirmation, and reanalysis differ by service. |
| Founder-only consumer report | Can identify selected common founder variants. | A negative result may leave hundreds of other known variants unassessed. |
Mayo Clinic cautions that some direct-to-consumer BRCA reports assess only three variants even though hundreds of pathogenic variants are known. This is especially important when interpreting founder-variant testing associated with Ashkenazi Jewish ancestry: a reassuring limited report is not comprehensive BRCA testing. [11,12]
A reassuring or negative WGS result is not the same as a negative clinical diagnostic result.
WGS does not guarantee detection or reporting of every clinically relevant variant and does not replace genetic counseling. Targeted clinical testing or confirmation may still be needed based on family history, a known familial variant, coverage gaps, or the result itself. [2,9,15]
If broader inherited health assessment fits your goals, see what the $599 genome service includes. Review the service’s current analysis and reporting scope with a genetics professional rather than treating it as a definitive BRCA test.
07 / 08
Common questions
What does a positive result mean?
A positive result usually means a laboratory found a pathogenic or likely pathogenic variant associated with increased cancer risk. It does not diagnose cancer. The next step is clinical confirmation when needed and a personalized discussion of screening and risk reduction. [1,9]
08 / 08
References and further reading
Sources were reviewed September 27, 2026. Risk estimates can change as evidence and clinical guidance evolve.
- 01National Cancer Institute. “BRCA Gene Changes: Cancer Risk and Genetic Testing.” Reviewed July 5, 2024.
- 02National Cancer Institute. “Genetic Testing for Inherited Cancer Risk.”
- 03NCBI Gene. BRCA1 DNA repair associated (Gene ID 672).
- 04NCBI Gene. BRCA2 DNA repair associated (Gene ID 675).
- 05MedlinePlus Genetics. BRCA1 gene.
- 06MedlinePlus Genetics. BRCA2 gene.
- 07U.S. Preventive Services Task Force. “BRCA-Related Cancer: Risk Assessment, Genetic Counseling, and Genetic Testing.” 2019.
- 08GeneReviews. “BRCA1- and BRCA2-Associated Hereditary Breast and Ovarian Cancer.”
- 09CDC. “Genetic Testing for Hereditary Breast and Ovarian Cancer.”
- 10Basser Center for BRCA. “BRCA in the Ashkenazi Jewish Community.”
- 11Mayo Clinic. “BRCA gene test for breast and ovarian cancer risk.”
- 12U.S. Food and Drug Administration. “Direct-to-Consumer Tests.”
- 13NCCN Guidelines for Patients. Genetic/Familial High-Risk Assessment: Breast, Ovarian, Pancreatic, and Prostate.
- 14GeneReviews. “Fanconi Anemia.”
- 15ACMG. “Technical standards for the interpretation and reporting of constitutional copy-number variants.”