The Results
Families with a BRCA1/BRCA2 mutation:
If someone in a family has a known genetic fault (MUTATION) in BRCA1 or BRCA2, testing other family members for that specific family
mutation can provide information about their own cancer risk. THIS IS CALLED PREDICTIVE TESTING. In this case, if a family member tests negative for the known family mutation they are at the same risk of developing breast and ovarian cancer as women in the general population. Women who receive a positive predictive BRCA1/BRCA2 result have inherited the increased risk of developing breast and ovarian cancer. Deciding to have a predictive test is a big decision. Some individuals chose not to take the test and have screening instead. They may change their mind in the future. Individuals may decide to have predictive testing to reduce the uncertainty about their cancer risk and help them to make decisions about their healthcare.
A positive test result may have important health and social implications for family members, including future generations. Unlike most other medical tests, genetic tests can reveal information not only about the person being tested, but also about that person's relatives. Both men and women, who inherit an altered BRCA1 or BRCA2 gene, whether or not they get cancer themselves, may pass the alteration on to their sons and daughters. Each child of people who have a gene mutation has a 50% (1 in 2) chance of inheriting the mutation.
High risk families without a BRCA1/2 mutation:
Many families with a strong history of breast and or ovarian cancer will not have a BRCA1/2 mutation. In these families the genetic testing is considered to be inconclusive rather than negative. This is because it is possible that the cancers in this family are due to a BREAST/OVARIAN CANCER gene that has not yet been identified. Further genetic testing may be available in the future, but in the meantime family members should discuss their management (Including breast screening) with their doctor.
Because everyone has genetic differences that are not associated with an increased risk of disease, it is sometimes not known whether a specific DNA change affects a person’s risk of developing cancer. If genetic testing shows a change in BRCA1 or BRCA2 that has not been previously associated with cancer in other people, the person’s test result may be interpreted as “a variant of uncertain significance".
In this case, the genetics team, including the laboratory staff and your doctor, will work together to find out as much as they can about this variant. In the majority of cases, the variants found are not harmful, and the family is in the same position as a family with an inconclusive result.
As more research is done into this area more gene faults will be found. And therefore families who tested inconclusive (but have a suspected gene fault) could be eligible for new gene tests in the future.
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