Information for People and Families with a Faulty Gene – BRCA 1

This information is to help you understand what it means to have BRCA 1 mutation. It is always important to seek advice and counseling from the appropriate health professionals including a Genetic Counselor and the relevant medical specialists.

What is the BRCA1 Gene?
BRCA1 (Breast Cancer gene 1) is a ‘cancer protection’ gene that helps to protect against breast, ovarian and some other cancers. Everyone has BRCA1 genes. If you have a faulty BRCA1 gene (mutation), your risk of developing these cancers is increased.

What is My Risk of Developing Cancer?

  • If you are a woman with a faulty BRCA1 gene you have about a 60% risk of developing breast cancer and about a 40% risk of developing ovarian cancer over your lifetime
  • If you are a male with a faulty BRCA1 gene you have about an 8% risk of developing prostate cancer by age 65 years and up to 6% risk of developing breast cancer over your lifetime
  • Not everyone who has a faulty BRCA1 gene will develop cancer

How is the Risk of Cancer Managed?
If you do have this gene mutation it is important that you seek advice from a genetic service or a family cancer clinic as they will be able to help guide you in managing your risk.

If you have a family member with the mutation but decide against genetic testing you should still be managed as if you do have the faulty gene.

Possible options include:

  • Regular breast screening by mammogram and sometimes magnetic resonance imaging (MRI) is important for women from the age of 30 to 50 (and earlier in some families). This combined with
    breast examination by a doctor aims to detect breast cancers early.
  • Some women may consider risk reducing breast surgery (mastectomy). Other options include the use of medications (such as tamoxifen/raloxifene)
  • Screening for ovarian cancer is unreliable and not recommended. Women with a faulty BRCA1 gene are encouraged to discuss removal of their ovaries and fallopian tubes (risk reducing salpingo-ophorectomy ,RRSO) with their doctors by the age of 40. As well as reducing the risk of ovarian cancer, this surgery also reduces the risk of breast cancer particularly if performed at or before 40 years of age. Decisions about starting a family or the timing of further children will need to be considered prior to surgery
  • Men with a faulty BRCA1 gene may consider having a yearly blood test (PSA) and examination from their early 40s after discussion with their doctor

What does this Mean for You and Your Relatives?
If you do carry a faulty BRCA1 gene:

  • You are at an increased risk of developing some cancers
  • The gene fault can be passed from one generation to the next, meaning each of your children has a 50% (or 1 in 2) chance of inheriting it. Predictive genetic testing is an option for them if their
    Genetic Health Professional knows which gene change has been identified in the family (see section on predictive testing).

If you do not have the faulty gene:

  • You are not at increased risk of developing cancers associated with the family gene fault, and have the same risk as the general population (unless there are other factors which may increase
    your risk)
  • You cannot pass it on to your children
  • Your siblings may still carry the faulty gene

Genetic Testing
Once a faulty BRCA1 gene has been identified in a family member, genetic testing (predictive testing) via a blood /saliva test is available to other adult family members to see if they have inherited the faulty gene. There are a number of significant emotional, psychological, family and practical issues associated with genetic testing which you and your family members should discuss with a Genetic Counselor.

For Doctors