BRCA Basics

What everyone should know

What are the BRCA genes?

BRCA is actually a general term for BRCA1 and BRCA2, two important genes in the human genome. They were discovered by geneticists in 1990 and found to play a significant role in preventing the development of breast cancer, which is how they received the name BRCA (BR for breast, CA for cancer; sometimes pronounced “brak-ah”), sometimes called Hereditary Breast Ovarian Cancer Syndrome (HBOC).

They are “tumor suppressor proteins” which normally control cell growth and cell death. These genes are important because they also help repair normal and abnormal damage that affects our DNA throughout our lives. Everyone (regardless of gender) has two copies of these genes in the DNA of every cell in their bodies. People are called carriers of BRCA1 or BRCA2 when they carry one normal and one abnormal or mutated copy of either one of these genes. That means that one copy of the genes functions normally to help suppress potential tumor development, while the other does not.

What does it mean to be a BRCA1 or BRCA2 carrier?

Having two copies of normally functioning genes is very helpful, because if one gene mutates spontaneously, the other copy can act as a backup and keep everything functioning as it should, while the body repairs the mutation. People who are carriers of BRCA1 or BRCA2 only have one functioning copy of these genes, which means if the other copy mutates (spontaneously), there is a a higher risk of it leading to the development of a tumour. Possible causes of mutated genes in life include chemical, physical, or biological environmental exposures, or chance errors during cell replication. This is why carrying a mutated copy of BRCA1 or BRCA2 is not a guarantee that the person will develop cancer. It just means that they have a higher risk of developing cancer than people with two normal copies of these genes.

What are the cancer risks for BRCA1 or BRCA2 carriers?

This is not a simple question and the answer depends on whether you are biologically male (XY) or female (XX), your age, what specific type of mutation you have, and many other factors. Generally speaking, carriers of BRCA1 and BRCA2 may be at increased risk of developing the following cancers:

  • Breast cancer (high risk in women; increased risk in men)

  • Ovarian cancer (in women only)

  • Prostate cancer (in men only)

  • Pancreatic Cancer

  • Small, but increased risk of several other cancers including melanoma, endometrial, laryngeal, colorectal, gastric cancers and lymphoma

BRCA carriers are also at higher risk of developing cancer at a younger age on average and the cancers that develop can often be more aggressive and resistant to treatment. Knowing your carrier status is powerful information. It can help you take preventative measures (whether you are female or male) and can help your doctors identify the best course of action for you in the case that you do develop a genetically-linked cancer. It also provides important information for your family, as this gene could be carried by other family members and can be passed on to your children.

You can find out more information about the risk of various cancers for male carriers here and female carriers here.

Can I pass BRCA1 and BRCA2 on to my kids?

We receive one copy of our genes from our mothers and one copy from our fathers. Because BRCA carriers have two copies of BRCA1 and BRCA2 genes (one normal and one mutated), carriers have a 50/50 chance of passing on a copy of these genes to their children. This is why it may be important for anyone to know their carrier status, regardless of their biological gender. Not only are men who are carriers at increased for cancers like aggressive prostate or pancreatic cancers, but they can also pass on these genes on to their daughters or sons.