Only a small number of Americans have undergone genetic testing to detect their or their future children’s disease risks, according to a new STAT-Harvard poll, but a majority say they would be interested in one day taking a genetic test that showed their risk of developing Alzheimer’s or cancer.
Physicians, however, are far less enthusiastic about the value of genetic testing for the general population, as shown by a separate poll of doctors commissioned by STAT, offering a possible explanation for why few people have undergone it.
“There is no evidence for doing this testing,” and there is “a lack of treatments available” to address whatever risks are identified, said Dr. Linda Girgis, who practices family medicine in southern New Jersey. “Until we have more large-scale studies showing the benefits of genetic testing, I doubt there will be much push to perform these tests.”
The STAT-Harvard T.H. Chan School of Public Health poll found that a large majority of Americans oppose more futuristic uses of genetics, such as creating “designer babies” by altering the DNA of embryos, but even genetic technologies available today are not being widely adopted. Celebrities such as actress Angelina Jolie have endorsed testing to identify genetic variants that raise the risk of disease, and companies such as 23andMe and Ancestry.com market their tests to consumers. Still, only 50 percent of Americans say they have heard or read about genetic testing, the poll found.
Only 6 percent of adults say they have undergone genetic testing. Of that group, 35 percent were driven by concerns about their future children’s health problems, 25 percent by a desire to learn more about their heritage or family history, and 18 percent by concerns about their own future health problems. Of those tested, 81 percent said it was “helpful” and 10 percent said it was not.
STAT-Harvard Poll on Genetic Editing, Testing, and Therapy
Based on a telephone poll of 1,000 US adults conducted January 13 - 17, 2016
Despite the low uptake so far, 56 percent of American adults would be interested in taking a genetic test that indicated their risk of developing Alzheimer’s disease or cancer.
Most Americans, 57 percent, believe such genetic tests for predicting disease are mostly accurate and reliable, while 24 percent believe they are not.
Read the full STAT-Harvard poll results
The STAT-Harvard telephone poll posed genetic testing questions to 480 randomly selected adults from January 13 to 17. Questions about people’s personal experience with testing were asked of an additional group January 20-24, for a total sample size of 1,489 people. The margin of error was plus or minus 5.3 percentage points for the smaller group, and 3.0 for the larger group. The results were weighted to reflect the demographics of the US adult population.
A survey of physicians offers clues as to why people are not exactly embracing genetic tests: doctors aren’t either. In an email survey of 1,609 US physicians (specialists from cardiology to neurology, as well as family physicians) conducted for STAT by Sermo, a social network site with 1.8 million health care professional members, 27 percent said they had recommended that their patients get their genome sequenced, while 73 percent had not. (Sermo asks a random sample of its members to participate in its polls, which have a margin of error of plus or minus 2.0 percentage points.)
One possible explanation for the lukewarm response: asked which they think is more informative for diagnosing and treating patients, 74 percent of doctors chose a family medical history and 26 percent chose genome sequencing.
While that might seem as if physicians are stuck in the 20th century, in fact, experts on genomics agree that skepticism is appropriate. “Family health history and clinical red flags, such as early age of onset of a breast cancer, is the best way to figure out if there might be a likelihood of heritable cancer, for example,” Dr. Charis Eng, chair of the Genomic Medicine Institute at the Cleveland Clinic, told STAT.
When doctors in the Sermo survey were asked why they would not recommend genome sequencing, the responses ranged from “It is not evidence-based,” and “I am not sure what the clinical benefit would be,” to “What does one do with [information indicating] you will eventually have a heart attack?”
One family physician asked, “What good would it do if you can’t change anything?”
Other physicians raised concerns about expense and lack of insurance reimbursement, or said it was “meaningless but frightening information” or would “open a Pandora’s box.”
Physicians who said they would recommend genome sequencing cited family histories of serious heritable diseases and hopes that genome sequencing could provide a diagnosis in cases of mystery diseases. Others cited the value of DNA information for identifying patients who might benefit from screenings and perhaps prophylactic surgeries, as with Angelina Jolie’s decision to have a double mastectomy in 2013 after she learned she carried BRCA mutations and then an oophorectomy (ovary removal) in 2015. Jolie underwent a specific DNA test, not whole-genome sequencing, whose value in clinical settings remains in doubt despite enthusiasm from some scientists.
Only 15 percent of the doctors in the Sermo survey said they had had a patient ask for help understanding the data from genomic testing done on their own through a company such as 23andMe or DNA4Life; 85 percent said it had never come up. Many doctors were willing to give genetic interpretation a try, despite reservations about their competence to do so: 63 percent said that if a patient brought in the results of a genomic test, they would help interpret the data, while 37 percent said they would not.
Only 47 percent said they believed in the validity of genetic data garnered through those consumer products; 53 percent said they didn’t.
“The push for genetic testing at this point [including in the popular press] is not based on science but is more an ‘in vogue’ thing,” Girgris said.
Genetic tests used in nutri- and functional genomics provide insight into function of enzymes (genes) in the metabolic pathways such as methylation and sulfuration, two very important pathways for health and vitality. They should not be used as predictors of disease since diet, lifestyle and environment determine how a gene is expressed. The gene testing is just one of several tools to assess risk, susceptibility, functional weaknesses/strengths and in that regard are very useful tools. Assessing function and identifying nutritional deficiencies and toxic burdens is not what medical practitioners are trained to do, so these tests are outside their scope.
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