internationalscholarship | summer school registration |
A new study casts doubt on the ability of advances in genetic science to predict whether people will get, or not get, a particular disease. The researchers stress that genes play only a partial role in causing illness, and so genetic information can provide only limited guidance on prevention or treatment.
As genetic sequencing becomes cheaper and cheaper, there is a lot of excitement about how knowing our own, individual genes will give us a road map of our future health prospects.
Not so fast, says Bert Vogelstein of Johns Hopkins University. "For the vast majority of individuals, whole-genome sequencing will never be a crystal ball that can reliably predict future health."
The problem is that disease can also be caused by environmental factors, like air pollution, or by random, unpredictable genetic mutations.
So for most people, being told that they have a genetic predisposition to disease when there isn't already a family history, is not really very useful information. "What is useful?" Vogelstein asks. "For example, suppose your risk for disease is one percent, and the testing increases it by five percent over that one percent. That's only 1.05 percent - not a significant difference."
That said, Vogelstein says some people may gain a lot from genetic testing. "For individuals with a strong family history of disease, whole-genome sequencing may well become extremely valuable."
To assess the value of whole-genome sequencing, Vogelstein and his colleagues used information about 55,000 pairs of identical twins - who start life with identical DNA, but often have very different medical histories as they age. By analyzing the differences in the medical history of each set of twin, the scientists were able to calculate the power of genes to predict future disease.
As the cost of this sort of genetic testing comes down, the companies that offer it are increasingly selling their service directly to consumers. Vogelstein and other scientists talk about the importance of having the results interpreted by a family physician or genetic counselor.
University of Pennsylvania epidemiologist Timothy Rebbeck, who was not involved in this research, puts it this way, "You wouldn't want to unleash this information on people without systems that allowed them to properly use and act on that information. And people could make all kinds of decisions that could harm them if they weren't completely aware of what it meant."
Vogelstein and Rebbeck spoke with reporters in Chicago at the annual meeting of the American Association for Cancer Research.
Không có nhận xét nào:
Đăng nhận xét