In a statement, the FDA said that the three mutations 23andMe's test evaluates are BRCA1/2 variants that occur most commonly in people of Ashkenazi Jewish descent. The variants may also be associated with an increased risk for certain other cancers.
"Some of the uses for which PGS is intended are particularly concerning", the FDA writes, "such as assessments for BRCA-related genetic risk and drug responses (e.g., warfarin sensitivity, clopidogrel response, and 5-fluorouracil toxicity) because of the potential health consequences that could result from false positive or false negative assessments for high-risk indications such as these".
The FDA today granted authorization for a direct-to-consumer test for a highly selected group of cancer-associated BRCA mutations. When they carry mistakes themselves, the fix isn't made, or it's made improperly. It can not determine a person's overall risk of developing cancer. In women, the presence of one of the variants increases breast cancer risk by up to 85 percent before age 70. About 45 percent of women with faulty BRCA2 genes will.
"There are other genes besides BRCA1 and BRCA2 for breast cancer, and there are lots of other mutations on BRCA1 and BRCA2 that aren't being tested". That accounts for a small percentage of people.
The newly approved 23andMe test will not find all of these mutations.
The test should also not be used by consumers or health care providers to decide on any treatments, including anti-hormone therapies and preventive removal of breasts or ovaries.
The FDA stresses that despite approving this first-of-its-kind test, the fact is that it only detects three out of 1,000 DNA abnormalities which can lead to cancer, so it shouldn't replace regular mammogram tests or trips to the doctor.
Things changed in a big way in 2017 when the FDA authorized 23andMe to provide direct-to-consumer DNA testing for 10 conditions like celiac disease, Parkinson's, Alzheimer's, and more.
Along with the approval, the FDA is setting up special controls to ensure the test's accuracy and performance, the agency said.