Beware the fortune tellers peddling genetic testsBMJ 2011; 342 doi: http://dx.doi.org/10.1136/bmj.c7233 (Published 06 January 2011) Cite this as: BMJ 2011;342:c7233
- Ray Moynihan, author, journalist, and conjoint lecturer, University of Newcastle, Australia
An enduring memory of my niece’s third birthday party is the fortune telling session that took place under the dining room table. A creative parent had donned a headscarf and extravagant earrings, and soon a line of toddlers were waiting to hear about the magic of their future. Given the state of the science a decade later it’s highly possible that this fortune telling was just as reliable as the high tech horoscopes arising from the marketing of genetic tests for common diseases.
When the US Government Accountability Office recently ran a covert operation on genetic tests for 15 common conditions, including Alzheimer’s disease, breast cancer, and restless legs syndrome, it uncovered the most extraordinary mess.1 It found that identical DNA samples produced wildly contradictory results. One donor was told by four different firms that he was at below average risk, average risk, and above average risk of having high blood pressure and prostate cancer.
Its report concluded that genetic tests marketed directly to the public were “misleading and of little or no practical use.” Yet hundreds of thousands of people worldwide are sending off samples of their saliva in good faith and receiving predictions that can have life changing consequences on the basis of tests that remain poorly evaluated and grossly under-regulated.
For anyone concerned about the creeping medicalisation of life, the marketplace for genetic testing is surely one of the latest frontiers, where apparently harmless technology can help mutate healthy people into fearful patients, their personhood redefined by multiple genetic predispositions for disease and early death.
Certainly there’s promise and hope among the hype, particularly when a rare single gene disorder may be involved. Researchers have used a genetic test to identify infants with a rare form of diabetes who benefited greatly from subsequent treatment.2 Yet there are many examples of false hopes. Recent findings have provided no good evidence that genetic testing benefits people who have a history of venous thromboembolism,3 those contemplating antidepressant treatment,4 or those wanting to identify their risk of developing cardiovascular disease.5
Once again a tool that’s proved useful in the laboratory has escaped like a virus into the marketplace, incubated by entrepreneurs, lazy reporters, and the power of our collective dreams of technological salvation, this time in the form of personalised medicine to treat us according to our individual genetic profiles.
Recent reports have welcomed the potential benefits of the different forms of genetic testing but warn governments to develop rational policy responses, to set enforceable rules for evaluating the technology, and to regulate its marketing.
A Nuffield Council on Bioethics report found that test results can be unreliable, be difficult to interpret, and cause further unnecessary testing.6 It concluded that many claims for individualised diagnosis and treatment “seem to be overstated and should be treated with caution.” A technology review commissioned by the UK Conservative Party found that results can be “inaccurate and misleading” and cited calls for “proper regulation.”7
Just before Christmas the Cambridge based Public Health Genetics Foundation decried the hype associated with “premature interventions” and argued that the biggest challenge now is to generate an evidence base so that we know when use of genetic information can improve global public health in a “safe, effective and cost-effective manner.”8 Likewise the medical literature is full of cautionary notes alongside the technology’s celebration, with one international group of researchers proclaiming that it could be decades before personalised medicine tailored to genetic profiles became a reality.9
The genetics researcher David Melzer and colleagues argued in the BMJ in 2008 that the science of genetic predispositions for common diseases was still so uncertain that onlookers may view it as “genetic astrology, producing entertaining horoscopes.”10 The authors concluded that marketing poorly evaluated tests in this evidence based age was an “unwelcome anomaly” and that “preventing misleading claims should also be a priority.” Others have made the valuable point that getting the regulation right might be as important as the science itself.
Evaluating genetic tests is a complex business, requiring assessment of how well the test measures what it claims to measure, how well the genetic variation predicts actual disease, how useful the results are in terms of treatment, and what the social and ethical issues might be. Clearly there’s potential for exaggerating the value of a genetic test, which is one reason Germany has imposed severe restrictions on direct to consumer testing. In the United States they’re talking of a new test registry on a government website, raising immediate concerns that it could lend legitimacy to unproved and potentially harmful products.
In Britain a government advisory body recently released a set of principles that it hopes will be taken up as a voluntary code of practice—a pusillanimous response already criticised as helping facilitate marketing rather than ensure proper regulation. Meanwhile the not for profit group GeneWatch UK warns that genetic tests may be used to sell unnecessary preventive drugs to healthy people and suggests that the tests be restricted to situations that produce health benefits and are ethically just.
Professor Melzer believes that there’s a much wider problem of poor evaluation of diagnostic tests. Governments, he argues, should simply create a kind of compulsory Wikileaks for tests, with full disclosure of evidence, “so people know what junk they’re buying.”
As for my niece, she’s now a flourishing teenager, still confident that the camel ride predicted under the dining room table will one day come to pass.
Cite this as: BMJ 2011;342:c7233
Competing interests: RM has published books on the medicalisation of life, including the 2005 Selling Sickness. His latest book is Sex, Lies and Pharmaceuticals. See www.raymoynihan.net.