April 18, 2018
In spring of 2018, the Food and Drug Administration (FDA) granted approval for consumer genetics company 23andMe to include information about breast and ovarian cancer risk caused by three BRCA1/BRCA2 mutations more prevalent among Ashkenazi Jews than other populations in the report it provides to users of its ancestry and health service. The FDA made their decision after a review process that determined that 23andMe’s test and results met appropriate benchmarks for accuracy. However, as the FDA’s press release noted, these three mutations constitute less than 1% of known BRCA1/BRCA2 mutations, and the receipt of these test results without guidance from a physician or genetic counselor may place individuals at risk for other harms.
The Norton & Elaine Sarnoff Center for Jewish Genetics cautions regarding the use of direct-to-consumer (DTC) testing such as the 23andMe test to determine one’s personal risk for hereditary cancer. Those who consider using such tests, or who receive such test results, should understand these key points:
- The results given by these tests are extremely limited and potentially misleading. The three mutations identified in 23andMe’s test represent only a small fraction of more than 1,000 known cancer-related mutations in the BRCA1/BRCA2 genes. Additionally, this test does not provide any information about mutations in other genes that can dramatically increase a person’s cancer risk. While the three BRCA mutations included in the 23andMe test are the more prevalent variants found in Ashkenazi Jews, it is possible for a Jewish individual to have a different mutation in BRCA1/BRCA2 or in another gene that increases their risk for cancer. Individuals with a significant personal or family history of cancer should consult with a genetic counselor or healthcare provider about more comprehensive testing options, as a negative 23andMe result does not eliminate the possibility of a different genetic mutation.
- Those who receive positive test results without assistance from a genetic counselor or qualified physician are not likely to have adequate preparation to understand their risk or evaluate appropriate preventative measures.
- Those who receive negative test results may not understand their remaining risks for hereditary or non-hereditary cancer. Only about 10% of cancers are directly linked to mutations such as those found in the BRCA1/BRCA2 genes. Some cancer is familial, but most cancer (about 70%) is sporadic, with no directly traceable genetic or familial component. A negative test result alone says very little about an individual’s ultimate risk for cancer.
- In almost all cases, physicians and genetic counselors who see patients regarding DTC results will and should recommend that patients get more comprehensive testing.
For individuals who have concerns about their hereditary cancer risk, we recommend:
- Meet with a genetic counselor, or with a physician or health care provider involved with cancer treatment and prevention.
- Discuss with that professional your personal and family history of breast, ovarian, and other cancers, what testing results can and cannot reveal, and the options that exist if a test reveals a mutation that increases risk for cancer.
The Norton & Elaine Sarnoff Center for Jewish Genetics offers a wealth of resources for persons who want to learn more about their risk and options for testing, prevention, and early detection. These resources include information on our website, JewishGenetics.org, and community access to a genetic counselor who is available to speak with concerned community members, provide education, answer questions, and direct individuals to appropriate clinical resources.