From car makers to cosmetic surgeons, everyone is scrambling to develop and market more economical products–and the consumer-genetics industry is no exception. DecodeMe, a division of Iceland-based Decode Genetics, launched two new services this week: a test that detects genetic variations associated with different cardiovascular diseases, and a screen that detects genetic variations linked to the risk of developing various cancers. At $195 and $225, respectively, the new tests are cheaper than Decode’s genome-wide screen, which for $985 assesses genetic risk for 34 diseases and traits ranging from diabetes to male-pattern baldness. “We wanted to give people an opportunity to buy a test that would only address their needs,” says Kari Stefansson, Decode’s president and cofounder.
But the same question that has plagued direct-to-consumer genetic testing since its inception remains: the clinical utility of such screens. “We have not sorted out what the best approach is for dealing with prostate-cancer risk in the normal population, much less in those who are at some increased risk,” says James Evans, a physician and geneticist at the University of North Carolina at Chapel Hill. He says that the same is true for other types of cancer.
The first test–deCODEme Cardio–detects eight genetic variations, known as single-nucleotide polymorphisms (SNPs), associated with the risk of heart attack, intracranical and abdominal aortic aneurysm, stroke and atrial fibrillation, peripherial arterial disease, and venous thromboempolism (clots in blood vessels). The second test–deCODEme Cancer–measures 29 SNPs associated with the risk of prostate, lung, bladder, colorectal, and breast cancers, as well as basal cell carcinoma.
The variations detected by the Decode tests clearly do increase risk of these diseases–in most cases, the link has been replicated numerous times. But they each boost risk of disease by a modest amount: typically 20 percent or less. In contrast, mutations in the BRCA1 gene, which physicians often screen for in women with a family history of breast cancer, boost a woman’s risk of developing breast cancer to between three and seven times that of someone who lacks the mutation. While the latter can help physicians recommend preventative measures, such as a mastectomy, it’s not yet clear how common variations of moderate effect can help shape an individual’s plan for prevention or treatment of disease.
“I’m very excited that these kinds of tests will allow us to provide better care for our patients, but we need to do more work to understand exactly what the true benefits will be from this kind of testing,” says David Herrington, director of the Translational Science Institute at Wake Forest University School of Medicine, in Winston-Salem, NC. This is true for any new risk-factor tests, he says, not just genetic ones.