An emerging trend in health care is the direct marketing of genetic test kits that give users their respective odds of developing a particular disease or condition.
The mail-in kits, marketed as “individualized medicine,” use saliva samples to identify small variations in the human genome (called “single nucleotide polymorphisms” or “SNPs”) associated with heightened risk for diseases such as diabetes and prostate cancer.
The kits come with price tags as high as $2,500.
Policymakers at the U.S. Food and Drug Administration have raised concerns about whether the tests are clinically beneficial and have advocated that they be conducted under medical supervision.
Of equal concern is the fact that few studies have investigated the emotional effects that direct-to-consumer genetic screens may have on patients.
In the October issue of Mayo Clinic Proceedings, a group of Mayo Clinic physicians and bioethicists analyzed whether these genetic tests cause patients to excessively worry about developing diseases.
“We looked for evidence of increased concern about disease based solely on genetic risk, and then whether the concern resulted in changes in health habits,” said co-author Clayton Cowl, M.D.
The randomized study found patients’ worry tended to be modestly elevated one week after the genetic testing, and that people worried more about unfamiliar diseases, for instance the thyroid condition Graves’ disease, than those commonly known, such as diabetes.
Researchers were surprised when a one-year follow-up suggested patients who had undergone testing were no more stressed than those who hadn’t.
Another unexpected result was that men whose genetic risk for prostate cancer was found to be lower than that of the general population, and who also had normal laboratory and physical screening results for the disease, were significantly less stressed about the disease than the control group.
Moreover, rather than worrying about the negative emotional state that could result from the test, experts believe the tests could be useful if they precipitate a change in health behavior such as losing weight or being vigilant about cancer screening.
On the other hand, patients who learn they have less-than-average genetic risk for a disease might skip steps to promote good health.
The current study assessed only the emotional effects of the tests.
“The ability to determine the actual utility of these tests, that is, whether a calculation of genetic risk accurately predicts disease, is still several years away,” said Cowl.
Source: Mayo Clinic