Things to consider before having a genetic test

There are lots of things to consider before deciding to have a genetic test. Although you may want to know that you have not inherited a cancer gene, you need to think about dealing with the news if you do have one.

There are advantages and disadvantages of having a genetic test. 

Advantages include:

  • If you do have a cancer gene mutation, this result can help you decide how to reduce your risk.
  • If you don’t have a cancer gene mutation, you will know that you can’t pass it on to your children.

Disadvantages include:

  • If you have a cancer gene mutation you may worry about getting cancer.
  • The result might be unclear.
  • If you have a cancer gene mutation you’ll need to think about telling relatives.
  • The result could affect your ability to get some types of insurance.

Without your approval your doctor can’t tell anyone you have had a genetic test, or the result.

When your blood is taken for the test, you may be asked if they can take a sample for research. This can help scientists to find other cancer genes. The scientists handling the sample won’t know your details.

Before having a genetic test

Your genetic specialist may talk to you about having a genetic test. They will usually do this if your family history shows you have a high risk of developing the cancer. Or if a close blood relative has had a test that found an inherited cancer gene.

There are several things to think about before having a genetic test. We have listed some of the possible advantages and disadvantages of having a genetic test below.

It’s natural to want genetic testing to find out you have not inherited a cancer gene. But you also need to prepare yourself for the news that you may have a cancer gene.

You may also want to think about how you feel about screening and other options for managing your cancer risk.

Before you have a genetic test, it’s important to know that you can handle the answer, because it’s not a piece of knowledge that you can unknow.


Possible advantages

  • If you find out you have a cancer gene mutation, this may help you to decide how to reduce your risk. Your options may include having screening to find cancer early, making lifestyle changes or having treatments to reduce your risk of getting cancer.
  • If the test shows you don’t have the cancer gene mutation in your family you won’t need to consider extra screening or risk-reducing treatments. You will know you can’t pass on the cancer gene to any children you have.

Possible disadvantages

  • If the test finds you have a cancer gene mutation, you may feel more worried about getting cancer. We have more information about having a high risk of cancer.
  • Tests don’t always give a clear answer. Some tests find a change in a gene but it isn’t known how this affects your cancer risk. We have more information about variants of uncertain significance.
  • If a test doesn’t find a gene mutation in the family, doctors may still assess your risk as high based on your family history.
  • If you have a test that finds a cancer gene mutation, you will need to decide whether or how to tell relatives. Many people find this difficult.
  • Insurers can’t ask you about the results of a genetic test for a cancer gene mutation. But this could change in the future (see below).
  • Through the testing process, you may find out things about your family that you didn’t know before. If you find out you are not related by blood to one or both of your parents, you won’t have the same genes as other family members. If this happens, there are people such as professional counsellors who can help if needed.


Some people worry insurance companies may discriminate against them if they have a genetic test. There isn’t a law to prevent this. But the Association of British Insurers (ABI) and the government have agreed to a temporary ban on asking people for the results of genetic tests for cancer. This is called the Concordat and Moratorium on Genetics and Insurance.

The Moratorium is in place until 2019 and will be reviewed in 2016. This means that the situation may change after the Moratorium expires in 2019.

The details of the agreement can be found on the ABI’s website. You can get a leaflet called 'Genetic tests and insurance: what you need to know' from the ABI website or by contacting them.

If you’ve had cancer already, or if several close relatives had cancer when they were younger, companies may increase your premium just because of your family history.

The same applies for private health insurance for cancer care and treatment. If you (or a high number of your relatives) have had cancer already, it will be harder (and more expensive) to get insurance cover.

If you have a predictive genetic test that shows you have not inherited the cancer gene in your family, you can tell insurers this. It may help to reduce your insurance premiums.


Your doctor cannot tell anyone you have had a genetic test, or the result, without your consent.

When they take your blood for the genetic test, they may ask if they can also take a sample for cancer genetics research. This may help scientists to find other cancer genes in the future. The sample is handled by other scientists who won’t know your personal details.

If you’re concerned about the confidentiality of your blood test information, ask your doctor or nurse about it. They will explain how your sample will be handled and who has access to it.

I gave consent for my sample to be retained and tested if future tests become available. It also means they can do research to find out what works for people.