In a move likely to heighten a longstanding controversy about DNA tests for health risks, the U.S. Food and Drug Administration (FDA) has ordered home genetic test maker 23andMe to “immediately discontinue” marketing its saliva collection kit and Personal Genome Service, charging that the company has made claims not backed with solid science.
The FDA warning letter contends that the Google-backed company has failed to show that its $99 test—which claims to check one’s risk for hundreds of diseases and conditions—is safe or effective. The regulators also point out that there could be potential for serious harm if the 23ndme test didn’t work as advertised.
“For instance, if the BRCA-related risk assessment for breast or ovarian cancer reports a false positive, it could lead a patient to undergo prophylactic surgery, chemoprevention, intensive screening, or other morbidity-inducing actions,” the letter states, “while a false negative could result in a failure to recognize an actual risk that may exist.”
In this scenario, if a woman was mistakenly told that she was a carrier of a BRCA1 or BRCA2 genetic mutation that put her at very high risk for breast and ovarian cancer, she might opt for an unnecessary preventive double mastectomy or undergo surgical removal of her ovaries, ending her fertility.
Also alarming is the possibility that women who are genuinely at high risk for these cancers (like Angelina Jolie) might be left dangerously in the dark if the DNA test incorrectly said they were not carriers of BRCA mutations.
It's easy to see the appeal of a simple home test that will uncover lots of interesting facts about your body and predict your risk of disease. But right now, it seems those tests are largely overhyped and can actually threaten your health by giving you false information.
Medically supervised genetic testing (performed in a doctor's office) is still a viable and accurate way to assess health risks for certain patients, but the at-home "direct-to-consumer" tests have been under fire since they hit the market.
A Lack of "Scientific Validity"
The FDA’s action comes after years of controversy about the accuracy of at-home genetic tests—also known as direct-to-consumer (DTC) tests—for health risks, which are offered online by such companies as DNA DTC, DNATraits, and GenePlanet.
One of these firms, DNATraits, had issues with the FDA in 2010, in connection with its Ashkenazi Jews Genetic Test Panel. At the time, 14 makers of genetic tests also received FDA letters, as part of a crackdown that also included an earlier warning to 23andme.
The Federal Trade Commission has long warned consumers that “some [DTC tests] lack scientific validity, and others provide medical results that are meaningful only in the context of a full medical evaluation.”
Genetic Testing Facilities and Cost
Last modified on September 17, 2012 at 6:55 pmLeer esta página en español
Testing for BRCA1 and BRCA2 is usually done on a blood sample taken in your doctor’s office and sent to a commercial laboratory or a research testing facility. Most people have it done by a commercial lab. During testing, the genes are separated from the rest of the DNA, and then they are scanned for abnormalities.
Often, the type of genetic testing that's done and the specific genes being tested dictate whether testing in a research setting is possible. Research labs tend to perform free and anonymous testing. But they may provide limited results or require multiple family members to participate. In addition, testing results may not be available for many months or years, and sometimes they're not available at all.
In the United States, Myriad Genetics performs all commercial BRCA1 and BRCA2 testing. They report results within a month. (Abnormalities in other genes have been associated with breast cancer risk. Right now, these appear to be a less common cause of breast cancer than BRCA1 and BRCA2 mutations, although research is ongoing. If you want to be screened for those, talk to your doctor and genetic counselor about where to be tested.) The cost of the BRCA test ranges from about $300 to $3,000, depending on whether you get the limited test, in which only a few areas of the gene are evaluated, or the full test, in which hundreds of areas are examined on both genes.
In 1988, the U.S. Congress passed the Clinical Laboratory Improvement Amendments (CLIA) to ensure quality standards and the accuracy and reliability of results across all testing laboratories. Genetic testing should be performed by a CLIA-approved facility. (Myriad Genetics is CLIA-approved.)
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