Here, two experts discuss the advantages and potential problems presented by the "genetic revolution".

Agnes Fletcher wants safeguards

Agnes Fletcher, from the Disability Rights Commission:

"There is no doubt that there is great potential for genetics to help us predict much earlier whether somebody will contract a disease, and to bring in treatment earlier. That can obviously have great benefits for people.

"But there is a lot of hype, and any expansion in genetic testing within the NHS should be matched by really good information and counselling for people.

"It is a complex area to understand what your risks might be. Genetic tests deal with increased risks, not certainties, and it is important that people have access to good information and support.

"They need to be able to think through the implications of having a test, and of how they might respond to the result, before they decide whether or not they want to go ahead with it.

"At the moment tests are only available on a limited basis, and if their use is to be expanded then it important that appropriate numbers of properly trained staff are made available.

"It is also very important that regulation and safeguards match expansion in the areas of research, testing and treatment.

"People can become vulnerable perhaps in the areas of insurance and employment.

"There is a lot of evidence of discrimination from the US, where these tests are more widely available, and although the US has a different healthcare system, it still serves as a warning.

"There is a voluntary ban in place affecting the insurance industry at the moment, but that is due to run out in 2006.

"We really need to be thinking now as a society about what we are going to do as information about people's future health becomes more widely accessible, and we would like to see anti-discrimination legislation put in place."

Dr Frances Flinter says testing is useful

Dr Frances Flinter, a consultant clinical geneticist:

"Gene testing is certainly advancing very quickly, and we do find it very useful to diagnose particular conditions, and also to help people identify whether they are carriers of certain genetic conditions, or whether they may have a condition which will develop when they are older.

"But I think there is a lot of hype, and a lot of people think that what we can predict with genetic testing is considerably more than is actually the case at the moment.

"It is important that anybody who is thinking about having a genetic test should see a professional within the NHS who is specifically trained to discuss the advantages and disadvantages of having such a test so they can make an informed decision.

"Nobody is ever going to be forced to have a genetic test, it is something that is available if people think it would be helpful to them.

"Our preference would be that genetic testing stays primarily within the NHS.

"We have a lot of concern about the use of DIY tests. It does potentially give people access to information which they may not be able to understand, which may not be presented in a very helpful way, and which may not even be accurate.

"There is also often a whole family that is affected by the implications of one person's genetic test results.

"What the regional genetic centres can offer is support and information for all the other relatives that might be affected as well."