The growth of home genetic-testing kits opens up a host of legal and ethical problems. Choice does not necessarily lead to empowerment, says Philip Ball.
The home pregnancy test, first marketed in the late 1970s, is the often overlooked complement of the contraceptive pill. It aided the 'sexual revolution' by allowing women and couples privacy and control over their fertility.
It is hard to find fault with a technology that enables women to determine privately whether they are pregnant, and it is tempting to regard the current emergence of home genetic-testing kits in the same light.
But this new area of 'personal medicine' is a minefield: medically, ethically and legally. Already, the genetics company DNA Direct in San Francisco offers home tests for genes implicated in cystic fibrosis, haemochromatosis ('iron overload disease'), thrombophilia (a blood-clotting disorder) and breast and ovarian cancer. This month, the company will make available a series of tests that analyse the most common genetic causes of infertility.
Power to the people?
The testing is simple: it is based on either a cheek swab or a blood sample, although like the first pregnancy test kits, these samples must be sent to a laboratory for diagnosis. DNA Direct claims that testing offers "peace of mind, prevention and healing" and that it will "help you lead a longer, healthier life".
The key to this technology is the buzzword 'empowerment'. Genetic testing, DNA Direct says, "can help you to take charge of your life and make decisions about health care, medical treatment, lifestyle choices and family life". If you know that you have a predisposition to certain types of cancer, that could provide otherwise elusive motivation to give up smoking or alter your diet.
And perhaps most significantly, private and confidential home testing could offer protection against 'genetic discrimination' in employment or insurance. US insurance companies currently require that if an applicant has information about their genetic makeup that could bear on, say, a life insurance policy, it must be disclosed. If this information has been obtained through a hospital test and is indicated on medical records, it is impossible to conceal. But if the test was done at home, who is to know?
Home genetic testing isn't a win-win scenario for the consumer, however. For one thing, knowledge is empowering only if it is understood. There is good reason to suppose (and simplistic reports of "the gene for X" have not helped matters) that public understanding of genetic predisposition to disease is hazy at best.
Moreover, the publicity surrounding initiatives such as the Human Genome Project have tends to encourage a belief in genetic determinism at the expense of other factors. "It's not clear that the consumer will be fully informed about the validity or value of these tests," says Sujatha Byravan, head of the Council for Responsible Genetics, a non-governmental organization based in Cambridge, Massachusetts.
Take DNA Direct's forthcoming 'genetic infertility' tests, for instance. It would be unfair to suggest that companies like this are seeking to profit from the vulnerability of infertile couples; but nonetheless such people often grasp at any treatment that seems to offer them hope.
They may decide that paying for the tests ($1,248 for men, $1,191 for women) is preferable to living with the worry that they passed up an insight into their condition. However, for one in three cases the causes of infertility are simply not apparent to routine tests, and a clear and treatable genetic cause is rare.
Genetic testing conducted at a doctor's clinic has to be accompanied by the option of counselling, both to help the patient understand the implications of the results and to help them deal with the emotional impact of bad news. DNA Direct recognizes the importance of such a service and offers its customers free access to qualified advisers.
But not all companies who offer such tests online do this. And it is not clear that home testers will be as inclined to take advantage of such services as those who have a test at a clinic.
There is currently no clear policy on the regulation of these home tests, and they do not have approval from the US Food and Drugs Administration. Francis Collins, head of the National Human Genome Research Institute in Bethesda, Maryland, questions the scientific validity of some of the claims that online companies are making.
James Healy of the UK Human Fertilisation and Embryology Authority says that home genetic-testing kits for infertility are "not something we'd recommend" because of the lack of guarantees about the quality of the service provided.
Legally, genetic testing is still highly controversial. The US Senate unanimously approved a bill in February to prohibit genetic discrimination in health insurance and employment.
In Britain, using predictive genetic tests to deny people insurance is currently prohibited. And on 14 March, the UK health secretary John Reid announced that the London-based Association of British Insurers have agreed to extend the prohibition until 2011.
The Council for Responsible Genetics argues that it is a violation of basic values for insurance companies to refuse to insure or increase premiums for individuals with 'risky' genetic profiles, partly because such genetic information is not deterministic.
But the problem is that this undermines the very basis on which the industry works. It already uses all sorts of other probabilistic data, such as information on age, lifestyle and gender, to determine premiums. Genetic discrimination may be unjust, but it is neither irrational nor unprecedented.
And the availability of home genetic testing, which gives customers 'inside' information, not only threatens to skew the insurance market but also seems to legitimize the withholding of such information.
The notion that choice equals empowerment is in any case a slippery one. For many parents in the current UK state education system, the option of choosing their children's school simply burdens them with the worry that they have failed by making the wrong choice.
Will a decision not to discover your children's genetic profiles with an off-the-shelf kit one day be regarded as a dereliction of parental duty?
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Ball, P. Test your own DNA. Nature (2005). https://doi.org/10.1038/news050314-16
Nature Biotechnology (2006)