If you are advised that you can undergo genetic testing, it will involve a simple blood test. The reason for that is that the geneticists will be looking for what they call your germline DNA. This is the DNA that’s in your whole body and they can get that from the white blood cells in a blood sample. Your sample will then be sent over to a genetics lab and there are several key genes that will be looked at routinely for those who’ve got a strong family history of breast cancer.
Before the blood test, one of the first things that happens is genetic counselling. This is where you’ll be talked to by a trained genetic counsellor about the chances of a mutation and what would happen if indeed you do have a mutation identified.
Additional counselling after the test is also provided if required and you can also then determine who in the family might also want to go through with genetic testing if a mutation was identified.
There are now 12 routinely tested genes: such as BRCA1, BRCA2, PALB2, ATM and CHECK2 (with more added since this video was recorded) and the geneticist will identify if you have a mutation in one of these genes. If a mutation is identified then there is a 50/50 chance that this could be passed on to each of your children.
It is actually quite rare and unusual for people to have a mutation such as this in the general population. However, the more cases of breast (and ovarian) cancer that there are in the family, and particularly the ages at which those cancers occurred, are important. So the younger the age that the cancers occur the more likely there is to be a mutation in these genes.
If you’re found to carry a mutation, and so have an increased risk of breast cancer, you will be eligible for more breast screening; starting at a younger age than the NHS breast screening programme and continuing for longer on an annual basis. This screening may also involve both magnetic resonance imaging (MRI) in addition to mammograms. As the risk of breast cancer is higher, you may also eligible for risk-reducing double mastectomy surgery and risk reducing medications such as tamoxifen.
Please contact your GP if you have any concerns and think you may be eligible for referral to the genetics team for genetic testing.