Imagine opening your mailbox to discover how likely it is you'll have a heart attack or whether you have a predisposition to Alzheimer's disease or cancer.
Thanks to advances in direct-to-consumer genetic testing, this scenario is moving from the realm of science fiction to reality.
Scientists are already using gene testing to diagnose certain diseases and prescribe medications. This testing is at the core of the burgeoning field of personalized medicine, which uses genetic information to prevent, diagnose and treat illness.
Many scientists believe the day is coming when DNA from a blood or saliva sample may be able to provide a comprehensive picture of a person's future health risks, enabling them to take preventive action.
A testament to the unbridled excitement surrounding the potential of personalized medicine is the federal government's announcement last month that it is pouring nearly $70-million into research in this area.
The private sector has also been quick to see its potential. A proliferation of genetic-mapping companies already sell pricey tests that promise to tell people what diseases or chronic illnesses may be lurking, what drugs could produce unwanted side effects for them and whether they could pass diseases to their offspring. Some can even detect traits such as high pain sensitivity, male-pattern baldness or athletic ability.
But a growing number of genetic specialists say the science is still too immature for these mass-market gene tests to hold significant value. Some are questioning whether direct-to-consumer genetic testing companies are overselling the science.
To renowned cancer specialist David Agus, the answer is no. He believes direct-to-consumer genetic testing represents the brave new world of medicine that finally puts the power of prevention in the hands of the people. In his provocative new bestseller The End of Illness, he makes the case that everyone could benefit from understanding their health risks and how to mitigate them with lifestyle changes or medications.
“Yes it can make you afraid, but at the same time, it empowers you,” Dr. Agus says. “It's the first of many technologies that will transform health care.”
He notes that public-health messages about the importance of exercising and eating right abound, but research shows that rates of obesity, Type 2 diabetes, cardiovascular disease and other serious health problems are escalating. The fundamental disconnect, according to him, is that none of the blanket messages espousing the importance of a healthy lifestyle seem to apply to anyone in particular. But looking at a piece of paper telling you that your genes make you vulnerable to a heart attack, cancer or an autoimmune disorder is a different story.
“It's a self-realization,” Dr. Agus says. “We have to prevent early disease and we can do that. We have the technology.”
But will people really change their behaviour based on the conclusions on a computer printout that cost hundreds of dollars? After all, many people continue to smoke, be overweight or drink too much, despite knowing it's bad for them.
“Information doesn't change human behaviour,” says Arthur Caplan, an ethics professor at the University of Pennsylvania.
But companies offering direct-to-consumer genetic profiles about disease susceptibility are only one small part of the equation. Doctors already routinely rely on gene testing to search for vital information.
For women with a family history of breast or ovarian cancer or who come from an Ashkenazi Jewish background, such tests can confirm whether their genes put them at high risk of those diseases. Some elect to have pro-active mastectomies or ovary removals, undergo frequent screening or take preventive medication.
Gene tests are currently ordered to confirm diagnoses on a range of conditions, such as cystic fibrosis and muscular dystrophy.
Yet, despite the promise of genetic testing, the science is still in its infancy. Because of that, many geneticists caution that the mail-order gene-profiling services may not be that useful.
