NEW YORK (GenomeWeb) – The US Food and Drug Administration today authorized 23andMe's genetic health risk report for three BRCA1 and BRCA2 mutations most commonly found in people of Ashkenazi Jewish descent.
"This test provides information to certain individuals who may be at increased breast, ovarian, or prostate cancer risk and who might not otherwise get genetic screening, and is a step forward in the availability of DTC genetic tests. But it has a lot of caveats," Donald St. Pierre, acting director of the Office of In Vitro Diagnostics and Radiological Health within FDA's Center for Devices and Radiological Health, said in a statement.
"While the detection of a BRCA mutation on this test does indicate an increased risk, only a small percentage of Americans carry one of these three mutations and most BRCA mutations that increase an individual's risk are not detected by this test. The test should not be used as a substitute for seeing your doctor for cancer screenings or counseling on genetic and lifestyle factors that can increase or decrease cancer risk."
Approximately 2 percent of women of Ashkenazi Jewish women have the three BRCA1/BRCA2 hereditary mutations, but they occur very rarely in other ethnic populations, in about 0.1 percent of individuals, if at all. All individuals, regardless of their ethnicity, may have other BRCA1/2 mutations or cancer-linked mutations in other genes not gauged by 23andMe's test. There are well over 1,000 BRCA mutations associated with breast and ovarian cancer risk, and dozens of other genes associated with cancer more broadly.
Most cancer cases, the FDA added, are due to non-genetic risk factors, such as obesity, smoking, and hormone use, and patients should consult their healthcare provider to discuss efforts to modify these risks. "The test … does not provide information on a person's overall risk of developing any type of cancer," the FDA stated. "The use of the test carries significant risks if individuals use the test results without consulting a physician or genetic counselor."
The FDA further noted that consumers and health care professionals should not use 23andMe's test results to make treatment decisions, including anti-hormone therapies and prophylactic removal of the breasts or ovaries, and that such decisions require confirmatory testing and genetic counseling.
In order to authorize 23andMe's BRCA test reports, the FDA reviewed data the company submitted via the de novo premarket review pathway for low-to-moderate-risk devices that are not substantially equivalent to a marketed device. The agency said it is also publishing special controls to outline its expectations for the test's accuracy, reproducibility, clinical performance, and labeling.
Previously the FDA has authorized 23andMe's Bloom syndrome test report, which opened the door for the company to broadly market carrier screening testing directly to consumers. Last year, the agency authorized the first crop of 23andMe's genetic health risk reports for DTC sales, but specifically restricted the intended use of such tests in prenatal testing, in determining cancer risk that leads to prophylactic screening or treatment, determining autosomal dominant variants, and pharmacogenetic testing.