Bloom Syndrome Carrier Status Test Approved

The U.S. Food and Drug Administration (FDA) recently approved a test for Bloom syndrome carrier status, marking the first time the agency has cleared the way for a direct-to-consumer test for a specific genetic condition. Bloom syndrome is a rare condition mainly affecting Ashkenazi Jews. The test is made by 23andMe, which is based in Mountain View, California.

Along with this approval, FDA also announced that it will now classify carrier screening tests as class II, and it will exempt such devices from the agency’s premarket review. It will issue a notice announcing its plan to exempt the tests and allowing for public comment for 30 days. This step is the “least burdensome regulatory path” for similar autosomal recessive carrier screening tests to enter the market, according to the FDA.

“The FDA believes that in many circumstances, it is not necessary for consumers to go through a licensed practitioner to have direct access to their personal genetic information,” said Alberto Gutierrez, PhD, director of FDA’s Office of In Vitro Diagnostics and Radiological Health in the agency’s Center for Devices and Radiological Health, in a prepared statement. “These tests have the potential to provide people with information about possible mutations in their genes that could be passed on to their children.”

Because such mutations are rare and due to the possibility of erroneous test results, professional societies usually suggest that the carrier screening tests only be used in parents with a known family history of a genetic disorder. “For example, when a gene mutation is expected to be very rare, a positive result for the mutation may have a high probability of being wrong,” FDA explained in a press release.

FDA is requiring companies to explain clearly in the test’s labeling what the results could mean for prospective parents. If the test is sold over the counter, 23andMe will be required to tell consumers how to find a board-certified clinical molecular geneticist or equivalent healthcare professional in order to receive both pre- and post-test counseling.

The 23andMe test is meant to be used only for postnatal carrier screening in adults of reproductive age. The company submitted research findings to the FDA, showing that the test is accurate in detecting Bloom syndrome carrier status. “One study conducted at two laboratories tested a total of 70 unique samples, including samples from known carriers of the disease. An additional study evaluated 105 samples at the same two laboratories. Both studies showed equivalent results in detecting carrier status of Bloom syndrome when the same samples were tested,” according to FDA’s news release. Additionally, 23andMe conducted a usability study with 302 people who were not familiar with the company’s saliva collection device in order to show that consumers could understand the instructions and collect an adequate saliva sample. The company also conducted a study of 667 participants in order to show that the test instructions and results were easy to understand and follow.

FDA previously issued a warning letter to 23andMe in 2013, directing the company to stop selling its Personal Genome Service “because of failure to obtain marketing clearance or approval to assure their tests were accurate, reliable and clinically meaningful,” according to the agency.