Parents offered genetic testing to predict their risks of common, adult-onset health conditions say they would also test their children. That is the finding of a new study published in the May issue of Pediatrics (published online April 18). The study authors note these and other findings should put pediatricians on alert that parents may chose predictive genetic tests for themselves and for their children, and seek guidance from doctors about what to do with the information.
Personal genetic tests are available directly to consumers at drug stores and over the Internet. They are controversial, and generally marketed to adults for their own use. However, it might be only a matter of time before parents become the focus of advertising campaigns targeting their children for testing, says Kenneth P. Tercyak, PhD, associate professor of oncology and pediatrics at Georgetown Lombardi Comprehensive Cancer Center, a part of Georgetown University Medical Center.
"The findings of our study should remind clinicians and policy-makers to consider children when regulating genetic tests," says Tercyak, the study's lead author. "These tests usually don't offer a clean bill of health and can be hard to interpret even in the best scenario. They identify incremental risks for many common diseases. Most people carry some risk based on a combination of their family history, genetics, and lifestyle. A child's unexpected test results could trigger negative reactions among parents and children, and lead to conversations at the pediatrician's office that providers aren't prepared to have."
The study, part of a larger effort by the National Human Genome Research Institute at the National Institutes of Health to assess the public's use of genetic tests, involved 219 parents who had been offered genetic testing for susceptibility to eight common, adult-onset health conditions (including colon, skin and lung cancer; heart disease; high cholesterol; and type 2 diabetes). The study mirrored health care consumer experiences and included online interactions with the researchers. Parents in the study were asked about their beliefs of the risks and benefits of predictive genetic testing for their child, as well as their interest in having their child tested if the test were made available. (No children were tested in this study).
Tercyak says the group of parents that were most interested in the test for themselves were interested in having their child tested too. In fact, parents made little distinction between the pros and cons of testing for themselves and for their children -- generally favoring the information, and believing it could lead to improved health maintenance, disease prevention, and other personal benefits during childhood and later on in the child's life.
Several professional organizations advise against predictive genetic testing in childhood for adult-onset conditions when the information has not been shown to reduce disease or death through interventions initiated early in life. But Tercyak says "Genetic testing for common disease risk could usher in a new era of personalized medicine. Someday, this type of information could help jump start conversations about lifestyle risks, and ways pediatricians can help parents and children reduce risk through healthier eating and exercise habits and avoiding tobacco and other substances. We still need to learn more about how to support families regarding choices on genetic tests and in adopting lifestyle changes, and what role high quality genetic information could play in those conversations."
Kirsten B. Hawkins, MD, MPH, an assistant professor of pediatrics at Georgetown University Medical Center and chief of the section of adolescent medicine at Georgetown University Hospital, agrees. "I counsel teens who are overweight and who have other concerns about their health because of certain diseases that run in the family." Hawkins says educating families about risks for disease is an essential part of prevention and wellness. "Someday", she notes, "the results of pediatric genetic tests could better inform these conversations. For now, encouraging parents and their children to avoid smoking, consume a well-balanced diet, and stay active are good advice for remaining healthy." (Hawkins was not involved in the study).
May 14, 2009
