BRCA Information & Genetic Testing
BRCA Genes and Inheritance*
Our genes come in pairs. Each cell in our body has two copies of each gene, including the BRCA1 and BRCA2 genes. We get one copy of each gene from our mother and one copy from our father. When we have children, we pass on one copy of each gene from each pair to our children.
For women, a BRCA mutation causes a higher risk for breast and ovarian cancers. Only one gene in the pair needs to have a mutation for you to have this risk. This is called “autosomal dominance.”
Men can carry the BRCA mutation, too. Men with a BRCA mutation have a lower overall chance of developing cancer than do women with a mutation, but their chances of breast, prostate and skin cancers are increased. In some men, BRCA2 gene mutations have been associated with an increased risk of lymphoma and cancers of the pancreas, gallbladder, bile duct and stomach. Futhermore, these cancers are more likely to develop at a younger age in men with a BRCA mutation.
If someone has a BRCA mutation, there is a 50% chance that they’ll pass it on to each child. There is also a 50% chance that they’ll pass on the gene without the mutation. So, knowing your BRCA status can be important for your children and other family members.
|Relative with a BRCA mutation||Chance you have a mutation||Chance you DON’T have a mutation|
|Child, Parent, Brother, Sister||50%, or 1 in 2||50%, or 1 in 2|
|Grandparent, Uncle, Aunt, Niece, Nephew||25%, or 1 in 4||75%, or 3 in 4|
|First Cousin||12.5%, or 1 in 8||87.5%, or 7 in 8|
Almost everyone with a BRCA mutation inherits it from a parent. Usually, that side of the family has a history of early breast cancer, ovarian cancer, or other cancers. Having a BRCA mutation doesn’t mean that you will definitely develop cancer, meaning not all family members with a BRCA mutation will have a cancer diagnosis.
If a BRCA mutation has been found in a family member, other relatives can find out their individual risk by testing to see if they inherited that mutation, too.
Gene mutations can’t “skip” a generation. If you don’t inherit a BRCA mutation, you can’t pass it on to your children.
* Source-El Camino Hospital
BRCA Genetic Testing*
What is genetic testing and what can it tell you?
Cancer genetic testing looks for the presence of an inherited gene mutation or alteration that increases the risk of developing cancer. It tells us why some families develop cancer more frequently than others, which individuals in a given family are likely to develop cancer in the future, and what types of cancer we should screen for in order to decrease cancer risk.
When is genetic testing recommended?
Genetic testing is recommended for individuals (men and women) with early onset cancers (usually before age 50), more than one cancer diagnosis, a strong family history of cancer or rare cancers such as male breast cancer or fallopian tube cancer. Individuals with Ashkenazi (central or eastern European) Jewish ancestry also are encouraged to seek evaluation, especially those with a family history of cancer.
What kind of testing is available and what is involved?
We conduct testing for all types of inherited cancer syndromes (breast, colon, ovary, etc.), including those with childhood onset such as retinoblastoma and von-Hippel-Lindau syndrome. The actual testing requires little more than a simple blood draw, but the process involves genetic counseling prior to testing. If a mutation is identified, the counselor will review current recommendations for medical management.
How are results of genetic testing used?
The results of genetic testing are most effectively used when shared with both physicians and family members. Sharing genetic information with physicians helps to insure appropriate management. Positive test results confirm high-risk status and give family members the opportunity to be proactive in reducing cancer risk.
If a gene alteration is identified, what can I/my family do to decrease cancer risk?
There are currently a number of options for hereditary cancer families. These include more frequent/earlier screening to increase the likelihood of early detection, taking medications to reduce the likelihood of cancer development and, in some cases, removing at-risk tissue before cancer occurs. Genetic counselors work closely with physicians to make sure that hereditary cancer families are managed according to the most recent guidelines for high-risk families.
Will insurance cover the cost of genetic testing?
Insurance companies often cover most or all of the cost of genetic testing. Eligibility for coverage depends on a combination of medical and family history. Having an early diagnosis of cancer (before age 50) and/or a strong family history of cancer increases the likelihood of insurance coverage.
* Source-Medical City Dallas
Contact a genetic counselor for more information.