This Associated Press story describes a new approach aimed at analyzing genetic data to assess the risk to patients of developing five specific diseases, and giving people a “polygenic score.” The new approach looks at multiple genes at the same time, and the role they play, in developing these diseases. Many current genetic tests focus on seeking individual genes that have been changed.
The story needed more caution–there are plenty of unknowns here. For example, even if a person knows their score, there’s no proof that having that number will improve health outcomes. What, for example, should a person do if they find out they’re at high risk for heart disease, but don’t have any signs of it? Also, false-positive and false-negative results could be significant.
Predicting a person’s risk for serious and life-threatening diseases is valuable, both to the individual and to public health. So any refined improvement in how we gauge that risk is a true benefit. But this story uses the findings from one effort looking at a British database and extrapolates too broadly without offering readers the kinds of information they need to gauge whether there is great promise here, or just more hype.
The story does say that the new approach “doesn’t require the most sophisticated type of genetic testing” — which is considerably expensive — adding that they (the researchers) can calculate “risk scores for those five diseases — eventually maybe more — simply by reanalyzing the kind of raw data people receive after sending a cheek swab to companies like 23andMe,” an at-home genetic test kit currently available. But it fails to point out that such kits themselves can be relatively expensive and currently wouldn’t be covered by most medical insurance plans.
The story has the researchers estimating that as many as 25 million Americans may have three times the average risk for coronary artery disease, even though their research used “a DNA database from Britain.” The story also says that the “scoring system also can predict an increased risk of Type 2 diabetes, inflammatory bowel disease, breast cancer and an irregular heartbeat called atrial fibrillation,” but doesn’t offer what those increases might be.
The big question goes unaddressed and unanswered: Is there proof this test will help anyone?
There’s no mention in the story about possible false positives or false negatives although both represent considerable concerns for individuals. False positives can cause patients unnecessary concern while false negatives may embolden persons to be careless in controlling other risk factors that can lead to disease.
For example, people with a high score may want to take cholesterol-lowering medications, which will have costs and potential side effects, without knowing whether they are effective. There also can be psychological harms of telling someone that that they have a high risk for cardiovascular disease or other diseases.
This story describes a new way of analyzing genetic data to supposedly better assess the risk a person has of developing specific diseases. They did that by running the data, “DNA and medical records from 400,000 people stored in Britain’s UK Biobank,” through their new “computerized system.” But the story fails to provide information on how well the new system predicted disease in those people. At the end of the day, what is important to most people is what exactly their individual risk might be, and the story offers no information on how well it evaluates that.
The story says that low-risk patients have a 1% risk of being diagnosed with coronary artery disease vs. 11% of those in the high-risk group. However we don’t know the time period over which diagnoses were made, nor exactly what is meant by coronary artery disease. This could range from a positive stress test to a massive heart attack.
No apparent disease mongering here.
The story does quote one source unaffiliated with the research effort and also points out that two of the researchers “are co-inventors on a patent application for the system,” so their potential for conflicts is clear to the reader.
The story does offer the following: “Other scientists and companies have long sought ways to measure risk from multiple, additive gene effects — the “poly” in polygenic — and Myriad Genetics has begun selling a type of polygenic test for breast cancer risk.” And there are multiple other methods for assessing the risk of a person developing specific diseases, although the story doesn’t offer any comparison between those methods and the new one it touts.
One of the researchers suggests that “in five years, each person will know this risk number, this ‘polygenic risk score,’ similar to the way each person knows his or her cholesterol,” making clear that the technology isn’t available to patients now. Moreover, the story adds that he “hopes to open a website where people can send in such data to learn their heart risk,” something that clearly doesn’t exist yet.
A genetic test capable of gauging a person’s risk of multiple diseases, based on a test looking for multiple genes, is clearly interesting enough to warrant a story, although the success of the test in actual practice with patients may be far less than the optimistic statements the story allows the researchers to make.
There’s no indication that this story relied on a news release.