"One issue raised in this study is the importance of educating health care providers in risk assessment based on family history and in strategies for communicating these family history-based risk results," said Dr. F. Sessions Cole, chief medical officer in the Division of Newborn Medicine at the St. Louis Children's Hospital.
"My sense is that most direct-to-consumer testing is used by a subset of the population who are both Internet-savvy and who can afford to pay out-of-pocket for these rather expensive tests," said Dr. Paul Fernhoff of the division of medical genetics at Emory University School of Medicine in Atlanta.
Dr. Bruce Korf, president of the American College of Medical Genetics, said, "There is also potential for misuse and-or misinterpretation of results, particularly given the lack of professional counseling that accompanies the results in some cases, and most of the results do not lead to clear actions to modify risk."
Korf also said there isn't much known about many genetic variants that may be involved in disease risk, so it's difficult to determine how clinically useful these personal screening tests are.
Doctors also say that while people are more aware that the tests exist, they don't think many people are using them, mostly because of the cost. Most of those who do, they say, are concerned about their risk for breast cancer.
Earlier this year, the U.S. Food and Drug Administration requested that five companies offering direct-to-consumer genetic testing submit the tests for scientific review to make sure they are accurate. Navigenics, the company that manufactures the personal genomic screening tool used in Eng's research, said in response that they are happy to cooperate with the FDA. But calls to Navigenics to respond to the the findings of Eng and her colleagues were not returned.
Another company that offers genetic testing, 23andMe, stands by their consumer tests.
"We are confident in our service's accuracy and reliability. It is widely accepted that the technology we are using is sound," the company said in its blog, The Spittoon.
In response to previous criticism that results from personal genetic tests often conflict with family history information, 23andMe said, "This is a criticism that could be said of any risk prediction."
Despite their skepticism, medical experts say personal genomic screening may someday prove its value.
Eng, who led the research comparing family history to personal genomic screening, said the results show more testing is needed to determine how useful personal screening can be.
"[P]ersonal genomic screening tests could potentially be more effective and accurate if combined with family health history information and used as a complementary tool for cancer risk assessment," Eng said.
Korf said, "I think that the data on risk of disease based on genomic screens will improve, and may become a component of routine medical care if the validity of these tests can be established and actions defined that can help people to respond to instances of increased risk."