People, it seems, don’t want to hear bad news–or they simply ignore it. In one study of smokers, scientists found that those who tested positive for a genetic variant that increased their risk of developing lung cancer were more likely to have forgotten the result six months later than those who tested negative. And preliminary results from a study sponsored by the National Institutes of Health suggest that healthy people aren’t particularly interested in this type of testing. In the study, scientists offer healthy people a prototype test that detects 15 genetic variants implicated in eight common health conditions, including diabetes, heart disease, high blood pressure, and lung cancer–all of which can be prevented or delayed by changes in lifestyle. But so far, only about 10 percent of those approached have chosen to take it. “We think they don’t see themselves as particularly vulnerable,” says Colleen McBride, a scientist at the National Human Genome Research Institute and the study’s leader.
If healthy people got interested in genetic testing, they would probably be the group to benefit most. If they were found to be at high risk, they could try to prevent even the first signs of disease. “Right now, we can’t get on the radar screen of healthy, young individuals because they don’t see themselves as susceptible to diseases that occur later in life,” says McBride. But new genetic tests “might be the kick start they need to engage them in the process,” she says. “The more personal the risk is, the more likely they are to react to it.”
When I first learned about my own risk for diabetes, I began exercising religiously and viewed white flour and sugar with suspicion, with the result that I dropped 30 pounds. Since then, my blood sugar tests have all been normal. As a result, my vigilance waned. That’s why I decided to order the test, which is almost as easy as buying a book from Amazon: a credit card and the time to answer a quick questionnaire about family history and other risk factors are all it takes. I sent in my DNA-coated swabs a few weeks ago and am awaiting my results. I realize that I’ll need to keep exercising and eating right regardless, but I want to know anyway, partly out of curiosity–a positive result could explain my own lengthy family history of diabetes–and partly because I think that for me, a positive result will provide extra motivation. Every little bit counts.
Update: For those of you who are curious, I finally got my test results last week. (Several weeks late, I might add.) I am negative for the high-risk allele. The results bring some relief, but not much. As my personalized report from DNA Direct points out, “Having a negative test result does not guarantee that you will never develop Type 2 diabetes.” I still have other risk factors for the disease.
In fact, the biggest relief had nothing to do with diabetes. Rather, it came from not having to publicly expose a genetic vulnerability. The Genetic Information Non-Discrimination Act, which would prohibit discrimination in employment or insurance on genetic grounds, is still lounging in the Senate, despite presidential support and a whopping margin (420-3) in the House of Representatives.
For me, the most fruitful aspect of getting tested was the reporting that went along with it. It forced me to face anew the seriousness of this disease and my own risk factors, and to talk about this with family and friends. When I told my mother about taking the test, she decided to talk with her own mother about my maternal grandfather and great-grandfather, both of whom died of diabetes-linked complications. The end result: a much more thorough family history than we had before.
If you want to beef up your own family medical history, check out My Family Health Portrait, a website created by the U.S. Department of Health and Human Services to help citizens create and share family health histories.
Emily Singer is the biotechnology and life sciences editor of Technology Review.