The U.S. Food and Drug Administration (FDA) recently authorized the sale of a new direct-to-consumer (DTC) genetic test that can provide some limited information on the risk of breast, ovarian, or prostate cancer for a small subset of people. The test is offered by the genetic testing company 23andMe as part of its health and ancestry service. It is the first DTC test for the three specific BRCA1/BRCA2 gene mutations that are most common in people of Ashkenazi (Eastern European) Jewish descent.
Consumers buy the test online directly from 23andMe and send a saliva sample to the company by mail. No healthcare provider is required to be involved. The company then analyzes the DNA in the saliva and sends a report directly back to the consumer.
The FDA's review of this test indicated that the test is accurate in identifying the three mutations it looks for and that the instructions and test results were generally easy for a consumer to understand. Before seeing test results, consumers must go through an education module. The test reports include information about what the results might mean, how results may be interpreted, and how consumers can find additional information about the results. According to a company spokesperson, the reports provide additional resources, including information on support groups, genetic counseling, and how to discuss results with other at-risk family members.
However, some experts are urging consumers who are considering the test to be cautious, given the test's significant limitations. For example, the three BRCA mutations detected by the test are relatively rare overall. While found in about 2% of Ashkenazi Jewish women, they are unlikely to be seen in people of other ethnic backgrounds (from 0 to 0.1%).
Additionally, there are more than 1,000 different BRCA mutations that are not detected by this test but that still cause a significant increase in risk for BRCA-related cancers for people of all ethnic backgrounds. So, absence of the three tested BRCA mutations does not mean that the person tested has no BRCA mutations and is at low or average risk. Only diagnostic testing ordered by a healthcare practitioner can fully evaluate the BRCA1/2 genes for these additional mutations. It is also important to remember that most cancers are not caused by an inherited genetic mutation but instead by other factors, such as environmental exposures and lifestyle choices.
"[This test] has a lot of caveats," said Donald St. Pierre, acting director of the Office of In Vitro Diagnostics and Radiological Health in the FDA's Center for Devices and Radiological Health. "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."
The FDA cautioned both physicians and consumers against using test results to start any treatments, including prophylactic surgery to remove ovaries and breasts—an increasingly common surgery for many women at high risk for breast and ovarian cancer. "Such decisions require confirmatory testing and genetic counseling," according to the FDA.
The American College of Medical Genetics issued a statement urging consumers who opt for the test to seek help from genetics experts to help decipher their results and overall risk. "Consumers who consider participating in [DTC] genetic testing must be aware of the limited results that they will receive and the types of questions that they will have to anticipate in the follow-up of the results. Appropriate counseling can be provided by medical geneticists and genetic counselors and may be done by other professionals who have acquired experience and training related to the particular genetic risks related to conditions in their area of specialty."
ACMG's website lists board certified genetic professionals and genetics clinics. The National Society of Genetic Counselors' website also has a "Find a Genetic Counselor" feature to locate a genetic counselor near you.