There Are More Than 1800 Mutations In The Brca1 And Brca2 Genes
Theres not one mutation of a single gene, but thousands and new mutations still get discovered. The DNA sequence of a gene can be altered in different ways, which is why mutations have different effects on health, depending on where they occur and how they alter the function of essential proteins.
Its important to know that not all mutations are pathogenic, meaning they dont always increase your susceptibility or predisposition for a disease. Some pathogens are more common in certain geographic areas or for people of certain descent .
Not all genetic mutations increase susceptibility or predisposition for a disease.
Genetic Testing For Brca Mutations
Overall, genetic testing for breast cancer genes is not standard. However, it is often recommended for women who have a family history of breast cancer or who have personally had breast cancer at a young age.
While you might have medical indications for getting tested, this is an emotionally charged decision. You may be faced with major decisions if you test positive for BRCA genes or other breast cancer genes .
Many women want to get tested in every way possible, while others prefer to avoid knowing about their risks.
Considerations as you make a decision about getting tested:
- If you are thinking about getting tested for breast cancer genes, you should speak with your healthcare provider and/or a genetic counselor before your test.
- If you’re struggling with the decision to move ahead with BRCA testing, you may benefit from having a conversation with your loved ones about how you might handle your results.
- Your health insurance carrier might cover the cost of genetic testing, but they might have criteria for coverage based on risk. If you are not considered high risk, you still can get tested and pay for it out of pocket, if you desire.
Regardless of your decision about genetic testing, you need to get your recommended mammograms.
Keep in mind that a negative test result does not mean that you will not get breast cancer. Likewise, testing positive doesn’t mean you will absolutely get breast cancer.
Are Harmful Variants In Brca1 And Brca2 More Common In Certain Racial/ethnic Populations Than Others
Yes. The likelihood of carrying an inherited mutation in BRCA1 or BRCA2 varies across specific population groups. While the prevalence in the general population is about 0.2%0.3% , about 2.0% of people of Ashkenazi Jewish descent carry a harmful variant in one of these two genes and the variants are usually one of three specific variants, called founder mutations. Other populations, such as Norwegian, Dutch, and Icelandic peoples, also have founder mutations .
Different racial/ethnic and geographic populations also tend to carry different variants in these genes. For instance, African Americans have BRCA1 variants that are not seen in other racial/ethnic groups in the United States . Most people of Ashkenazi Jewish descent in the United States who carry a BRCA variant have one of three specific variants . In the Icelandic population, a different variant in BRCA1 is common among those who inherit a mutation in BRCA1.
Study: New Genes Linked With Triple Negative Breast Cancer
A research study identified new genes that may be associated with a higher risk for triple negative breast cancer.
This image is an example of the kind of gel pictures researchers use to understand the order, or sequence, of genes or to look for mutations in genes.
This image is an example of the kind of gel pictures researchers use to understand the order, or sequence, of genes or to look for mutations in genes.
Out of 100 people with breast cancer about 15 will have triple-negative breast cancer . Its one of the most challenging types of breast cancer to treat due to several things:
- TNBC tends to be more aggressive than other common types of breast cancer.
- Women usually dont learn they have it until the cancer has already spread to other parts of the body .
- Treatment options remain limited.Hormone therapies and targeted therapies that help treat people with some types of breast cancer, typically dont work for a woman with TNBC. Doctors use chemotherapy to treat these patients, but it isnt very effective and may have side effects.
If doctors had a way to identify women at risk for TNBC, they might be able to find cancer earlier and before it spreads when it might be easier to treat. And, if doctors had a way to personalize treatment for women with TNBC, they might be able to improve a womans outlook . One approach researchers are using to identify women at risk for TNBC and possible treatment options for TNBC is by studying inherited changes in cancer genes.
Referral To A Specialist
Your GP will refer you to a specialist breast clinic or genetics clinic for assessment if you have any of the following:
- one first degree female relative diagnosed with breast cancer aged younger than 40
- one first degree male relative diagnosed with breast cancer at any age
- one first degree relative with cancer in both breasts where the first cancer was diagnosed aged younger than 50
- two first degree relatives, or one first degree and one second degree relative, diagnosed with breast cancer at any age
- one first degree or second degree relative diagnosed with breast cancer at any age and one first degree or second degree relative diagnosed with ovarian cancer at any age
- three first degree or second degree relatives diagnosed with breast cancer at any age
Your GP should also refer you if you have one first degree or second degree relative diagnosed with breast cancer when they were older than 40 years and one of the following:
- the cancer was in both breasts
- the cancer was in a man
- ovarian cancer
- Jewish ancestry
- sarcoma in a relative younger than age 45 years
- a type of brain tumour called glioma or childhood adrenal cortical carcinomas
- complicated patterns of multiple cancers diagnosed at a young age
- two or more relatives with breast cancer on your father’s side of the family
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Brca1 Gene And Prostate Cancer
Researchers have looked at the BRCA1 gene, which increases the risk of breast and ovarian cancer. The situation with prostate cancer is less clear and some studies have found that it doesnt significantly increase the risk of prostate cancer. We need more research to find out whether it does increase the risk.
A trial is looking at men who have an increased risk of developing prostate cancer because they have faulty BRCA1 or BRCA2 genes. The trial is looking at whether a blood test called prostate specific antigen combined with a biopsy, is a good way of picking up prostate cancer early in these men. It is called the IMPACT study.
Brca Mutations And Other Cancers
Ovarian cancer occurs in roughly 1.3% of women in the general population. For those with BRCA1 mutations, 39% are expected to develop ovarian cancer, while 11 to 17% of those with a BRCA2 mutation will develop the disease.
There are other cancers that can be associated with BRCA mutations as well, such as prostate cancer, pancreatic cancer, and lung cancer.
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What To Do If Youre Concerned About Your Family History
If youre concerned about your family history of breast cancer, you may be able to have a family history risk assessment. A family history risk assessment will try to find out if you are at general population, moderate or high risk of breast cancer. Listen to a discussion of family history FAQs with one of our nurses.
The first step is to talk to a healthcare professional. Who you should talk to first will depend on your situation.
- If you have not had breast cancer yourself, you can talk to your GP , who will ask about your family history and may refer you to a specialist family history clinic or a regional genetics centre .
- If you have been diagnosed with breast cancer yourself, you can speak to a member of your specialist breast care team who will be able to refer you to a specialist family history clinic or a regional genetics centre if appropriate.
You should be referred for further assessment of your risk if:
- you or one close relative has had breast cancer before the age of 40
- you or one close relative has had breast cancer in both breasts
- you have had breast cancer known as triple negative
- you and one close relative have had breast cancer
- two or more close relatives have had breast cancer
- you have close relatives who have had breast cancer and others who have had ovarian cancer
- a male relative has had breast cancer
- you are of Ashkenazi Jewish ancestry.
You might also be referred if:
What Do Brca1 And Brca2 Genetic Test Results Mean
BRCA1 and BRCA2 mutation testing can give several possible results: a positive result, a negative result, or a variant of uncertain significance result.
Positive result. A positive test result indicates that a person has inherited a known harmful variant in BRCA1 or BRCA2 and has an increased risk of developing certain cancers. However, a positive test result cannot tell whether or when the tested individual will develop cancer. Some people who inherit a harmful BRCA1 or BRCA2 variant never develop cancer.
A positive test result may also have important implications for family members, including future generations.
- Both men and women who inherit a harmful BRCA1 or BRCA2 variant, whether or not they develop cancer themselves, may pass the variant to their children. Each child has a 50% chance of inheriting a parents variant.
- All blood relatives of a person who has inherited a harmful BRCA1 or BRCA2 variant are at some increased risk of having the variant themselves. For example, each of that persons full siblings has a 50% chance of having inherited the variant as well.
- Very rarely, an individual may test positive for a harmful variant not inherited from either parent. This is called a de novo variant. Such a variant is one that arose in a germ cell of one of the parents and is present in all the cells of the person who grew from that cell. The children of someone with a de novo variant are at risk of inheriting the variant.
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Psychological Effects Of A Positive Test
If you or a relative have tested positive, you may become overwhelmed with worry about breast cancer. This reaction is not usual, but you owe it to yourself to sort out your feelings about the issue. If you are pre-occupied with the risk of breast cancer, it can help to talk to a therapist who can listen to you and provide you with strategies to cope with your feelings and apprehensions.
How Are Brca1 And Brca2 Genetic Mutations Passed Down Through A Family
BRCA1 and BRCA2 genetic mutations can be passed from a mother or father to a son or daughter.
People with a first-degree relative with a BRCA1 or BRCA2 mutation have a 50% chance of having inherited themutation.
Mutations in the BRCA1 and BRCA2 genes have been found in people all over the world. However, some genetic mutations may be more common in certain ancestral groups. For example, three BRCA1 and BRCA2 genetic mutations are particularly common among Ashkenazi Jewish families. Ashkenazi Jewish families typically have origins in Eastern Europe. One in 40 Ashkenazi Jewish individuals carry one of these common BRCA mutations.
Through MSKs RISE Program, our experts help people who have an increased risk of breast cancer shape personalized long-term surveillance plans.
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Guidelines For Genetic Testing For Breast Cancer
About 10% of breast cancers are related to inheritance of damaged genes. BRCA1 and BRCA2 are the genes most frequently implicated, but there are many other genes, such as PALB2, ATM, and CHEK2, that need to be considered as well. Genetic testing usually starts with a family member who has already developed a breast or ovarian cancer. If this individual is positive for a mutation then all of the other family members can be tested for the same mutation to determine who is high risk and who is not. If no one in the family is known to carry a mutation then the test is considered non-informative. That means the test was unable to tell us which relatives in the family are high risk. People who have inherited a damaged gene are at increased risk for breast and other cancers. The risk may be as high as 80% depending on the specific gene and family history. Guidelines for determining whether an individual should get genetic testing or not are constantly evolving. General criteria include:
- Someone in your family is known to carry a mutated gene
- Ashkenazi Jewish ancestry
- You were diagnosed with breast cancer before age 50
- A man in your family has been diagnosed with breast cancer
- You were diagnosed with ovarian cancer
- There are multiple breast cancers on one side of your family
- Cancer was diagnosed in both breasts
If You Have A Faulty Gene
If you have a faulty gene that increases the risk of ovarian cancer, what happens next will depend on which gene you have. Your specialist may suggest regular screening. Researchers are looking into the best way to do this. Or, depending on your age and whether youve had all the children you want to have, you may choose to have surgery to remove your ovaries and fallopian tubes.
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Surgery Is Not The Only Option For Brca Carriers
Having a bilateral mastectomy and having your ovaries and/or fallopian tubes removed is not the only option. If you have a BRCA gene mutation, you can opt for regular screenings and other preventative measures until youre ready for operation. This probably depends on the country youre living in and your health insurance, but there are always options. The options available to you should be presented to you during your genetic counseling.
But sadly the best preventative measure against breast cancer is a mastectomy, and even that doesnt completely eliminate risk, it only reduces it. Because they cant remove every single cell of breast tissue, there is still a 2-5 % risk of breast cancer after a mastectomy.
Salpingo-Oophorectomy is the best way to reduce risk for ovarian cancer.
What Causes Hboc
HBOC is an inherited genetic condition. This means that the cancer risk is passed from generation to generation in a family. There are 2 primary genes linked with most families who have HBOC: BRCA1 and BRCA2. BRCA stands for BReast CAncer. A mutation, or harmful genetic change, in either BRCA1 or BRCA2 gives a woman an increased lifetime risk of developing breast and ovarian cancers. Men with these gene mutations also have an increased risk of breast cancer and prostate cancer. There is a slight increase in the risk of other cancers including pancreatic cancer and melanoma among people with BRCA1 or BRCA2 mutations.
Not all families with multiple cases of breast and ovarian cancer have mutations in BRCA1 or BRCA2. There are also other genes that have been linked with an increased risk of developing breast and other cancers, such as mutations in the TP53, PTEN, CDH1, ATM, CHEK2, or PALB2 tumor suppressor genes and others. Blood tests now include many of these genes,including BRCA1 or BRCA2, in a single, multiple-gene panel test.
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What Is A Gene
Each persons DNA contains the code used to build the human body and keep it functioning. Genes are the small sections of DNA that code for individual traits. For example, someone with naturally red hair has a gene that causes his or her hair to be red.
All inherited traits are passed down through genes. Each person has two copies of every gene: one gene from each parent. Since each parent passes down exactly half of their genes to each child, any of the parents genetic traits has a 50% chance of being passed on to their offspring.
Does Your Family Health History Put You At Risk
Collect your family health history of breast, ovarian, and other cancers and share this information with your doctor. You can inherit BRCA and other mutations from your mother or your father, so be sure to include information from both sides of your family. Include your close relatives: parents, sisters, brothers, children, grandparents, aunts, uncles, nieces, nephews, and grandchildren. If you have had breast, ovarian, or other cancers, make sure that your family members know about your diagnosis.
Tell your doctor if you have a personal or family health history of any of the following:
- Breast cancer, especially at a younger age
- Triple-negative breast cancer at age 60 or younger in women
- Cancer in both breasts
- Breast cancer in a male relative
- Ovarian, fallopian tube, or primary peritoneal cancer
- Pancreatic cancer
- Metastatic or high grade prostate cancer
- Breast, ovarian, pancreatic, or high grade prostate cancer among multiple blood relatives
- Ashkenazi or Eastern European Jewish ancestry
- A known BRCA mutation in the family
You can use the My Family Health Portrait tool to collect your family health history information and share this information with your doctor and other family members. Update your family health history information on a regular basis and let your doctor know if any new cases of breast or ovarian cancer occur.
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