Before you decide to have a genetic test you need to think about how you would feel if you found out that you had one of the gene changes that very much increase your risk of getting cancer. Some people want genetic testing in order to find out that they are all right and haven't inherited a genetic mutation. But, before you go ahead with testing, you need to prepare yourself for possible bad news too. You might want to consider how you feel about the screening and the options for reducing your risk of cancer that are available if you have a positive test result. You will usually be offered two or more counselling sessions before having genetic testing; it is important that you take as much time as you need before deciding whether or not to have the test.

Through the testing process, you might also find out other things that you did not know before. Genetic testing is family-based, so if you are not related by blood to one or both of your parents, for example, if you were adopted or because of family secrets, you don't share your genes with all your family. It is possible that through talking about familial risk and family relations you could suddenly discover things you didn't know about your family. It can be quite a shock to find out facts about your family that you weren't aware of. If this happens to you, there are people who can help, including professional counsellors.

There are companies that provide private genetic testing in the UK and Ireland for:

• breast and ovarian cancers
• inherited bowel cancers
• inherited skin cancers.

They will usually deliver the results of tests within 3–4 weeks. You will have to pay for these tests.

Private genetic testing services may not offer you genetic counselling to help you consider the implications of genetic testing for you and your family. If you are considering having a genetic test outside the NHS, it is still a good idea to discuss your thoughts with a genetic counsellor in order to clarify your family risk (based on your family history) and also to consider the wider implications of genetic testing for yourself and your relatives.

Some people are worried that once they have had a gene test they might be discriminated against, for example, by insurance companies. There is currently no legislation in the UK that explicitly prevents discrimination on the basis of genetic differences. However, there is a voluntary agreement (called the Concordat and Moratorium) between the Department of Health and the Association of British Insurers (ABI). This is in place until 1 November 2011. It is unclear what the situation will be after that.

In the agreement, amongst other things, insurers give ten commitments on the information that they will ask of customers. For example, customers will not be asked to:

• have a predictive genetic test in order to obtain insurance
• tell them about a family member's test results
• tell them about any predictive or diagnostic genetic test results acquired as part of clinical research
• tell them about any predictive test results that are made available after their policy has started, for as long as that policy is in force.

The Moratorium (which forms part of the Concordat) ensures that customers will not be required to disclose the results of predictive genetic tests for policies up to £500,000 of life insurance, or £300,000 of critical illness insurance. Over these financial limits, insurers can only ask about predictive tests that have been approved by the Genetics and Insurance Committee (GAIC). GAIC is an advisory public body that reports to the Government. At the moment, the cancer susceptibility genes are not on the list of genetic tests that have been approved by GAIC, and so cannot be asked about by insurance companies (above the limits of £500,000/£300,000). However, this may change in the future.

The details of the agreement can be found online on the ABI's website (www.abi.org.uk/Display/File/Child/106/Concordat_and_Moratorium.pdf) or can be obtained from the Department of Health, 652 Skipton House, 80 London Road, London SE1 6LH tel 020 7972 1518/fax 020 7972 1717). You can get a leaflet called Genetic Tests and Insurance: What You Need to Know from the ABI or via its website: www.abi.org.uk

However, if you have had cancer already, or if many of your close relatives have had cancer at a relatively young age, insurance companies might increase your premium simply 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. Under the terms of the Concordat, insurers agree that customers may choose to disclose predictive genetic test results that are in their favour in order to override family history information. Most insurers will take the result of such a test into account, provided that the result is from a reputable source.

Your doctor is not allowed to tell anyone that you have had a gene test or what the result is. When your doctor or nurse takes your blood for the gene test they might also ask you whether they can use the blood sample for research in the area of cancer genetics. This might help scientists to find other cancer genes in the future. If you agree that your blood sample can be used for research purposes, it will be handled by other scientists, but they won't be able to find out your personal details.

In very rare circumstances, the courts have authorised the police or lawyers to use the information contained in medical and research databases.

If you are concerned about the confidentiality of your blood test information, feel free to ask your doctor or nurse about it. They will be able to explain how your sample will be handled and who can have access to it. You can also contact Cancerbackup with questions about clinical research and confidentiality.

If your family history suggests that the cancers in your family might be caused by a genetic factor, but you decide not to have a genetic test, you will be offered all the services (cancer screening, prevention) available to people at higher risk. You do not need to have a genetic test in order to have screening.