• Who is offered genetic testing
• At what age is genetic testing performed?
• Why is it important to identify the BRCA mutation within a family?
• Will I be able to get insurance if I have genetic testing?
• How can I prevent passing on the BRCA mutation to my children?
In the UK and Ireland, specialist genetic clinics assess when genetic testing is appropriate. Whether a person has breast or ovarian cancer, or has a strong family history of breast and ovarian cancer, genetic testing is offered when it is considered that the probability of them carrying a mutation is greater than 10%
Who is offered genetic testing?
Not all women diagnosed with breast or ovarian cancer will be offered genetic testing. When it is considered that there is more than a 10% chance of a mutation being found genetic testing will be offered. This includes:
women with a strong family of breast and ovarian cancer women diagnosed with a triple negative breast cancer before age 50
women diagnosed with breast cancer before age 35
women diagnosed with a serous ovarian cancer below the age of 60
This form of genetic testing is called a “mutation search”
When the genetic test finds a BRCA mutation that is known to increase the risk of breast and ovarian cancers, the test is said to be positive. In some cases a small gene mutation is found where there is not enough information to know whether that mutation is responsible for the cancer. These mutations are called “variants of unknown significance” (VUS) and your geneticist will advise as to whether the test should impact your treatment options and whether genetic testing of other family members is required.
If a genetic mutation has been found such as BRCA1 and BRCA2 testing can then be offered to parents, siblings and children who have a 50% chance of inheriting the gene mutation. This predictive genetic testing is only looking for the specific fault that has been identified in the family member
At what age is genetic testing performed?
BRCA mutations are not associated with any increased risk of cancer in children or teenagers. Only when a young person turns 18 are they considered an adult and able to consent to genetic testing.
There is no risk of cancer before the age of 25 and in the U.K. breast screening does not start until a woman with a mutation is 30 years old so nothing will change if a woman waits until she is about 25 years old before requesting testing. Young men are not at risk of breast or prostate cancer until they are in their forties and may delay testing until they are older.
Why is it important to identify the BRCA mutation within a family?
The knowledge of a BRCA mutation in a family will help to explain why there have been cancers in family members. An individual shown to carry a mutation has the opportunity of having higher risk breast screening and taking measures to reduce their risk of cancer.
If someone already has been diagnosed with cancer the knowledge that they carry a mutation will enable them to be considered for more targeted chemotherapy and can take steps to reduce the risks of further cancer.
Will I be able to get insurance if I have genetic testing?
There is a concordant and moratorium regarding genetics and insurance agreed with insurance companies. Information may be requested about your family history of cancer but not about genetic testing for BRCA mutations. This means there is no detrimental impact of genetic testing and more details can be obtained by visiting their website (www.abi.org.uk)
You can voluntarily disclose the results of a predictive test to your insurer and a negative test result may counteract a higher premium based on your family medical history.
How can I prevent passing on the BRCA mutation to my children?
It is now possible for pre-implantation genetic diagnosis (PGD) to enable people with an inheritable condition to avoid passing on the mutation to their children. The Human Fertilisation and Embryology Authority who have responsibility to oversee the use of embryos in fertility treatment and research have listed BRCA1 and BRCA2 as two of the conditions where PGD can be offered to couples.
This means that couples use IVF treatment and the embryos created and tested only the embryos that are shown not to carry the mutation are transferred to the womb to develop. The risks involved with PGD are similar to those for conventional in vitro fertilisation. Children who have had PGD have health and development that is no different to children who are conceived naturally.
This is not an easy decision for couples where one of them carries a BRCA mutation. PGD is more commonly offered for genetic conditions that result in serious debilitating life limiting diseases. Couples need to be aware that IVF treatment is not easy and can be an emotional rollercoaster. They may ask themselves what decision would they make if three embryos were tested and they were all shown to carry a BRCA mutation, would they be prepared to discard all embryos and forego the possibility of a pregnancy?
Some couples may choose to use donor eggs (if mum is the carrier) or donor sperm (if dad is the carrier) as an alternative way to avoid passing on the BRCA mutation to their children.
Couples who want more information regarding this should ask to be referred to their local genetic clinic for further consultation.