The U.S. Food and Drug Administration today authorized for marketing 23andMe’s Bloom Syndrome carrier test, a direct-to-consumer (DTC) genetic test to determine whether a healthy person has a variant in a gene that could lead to their offspring inheriting the serious disorder.
Along with this authorization, the FDA is also classifying carrier screening tests as class II. In addition, the FDA intends to exempt these devices from FDA premarket review. The agency plans to issue a notice that announces the intent to exempt these tests and that provides a 30-day period for public comment. This action creates the least burdensome regulatory path for autosomal recessive carrier screening tests with similar uses to enter the market.
“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. Today’s authorization and accompanying classification, along with FDA’s intent to exempt these devices from FDA premarket review, supports innovation and will ultimately benefit consumers,” said Alberto Gutierrez, Ph.D., director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health. “These tests have the potential to provide people with information about possible mutations in their genes that could be passed on to their children.”
In general, carrier testing is a type of genetic testing performed on people who display no symptoms for a genetic disorder but may be at risk for passing it on to their children. A carrier for a genetic disorder has inherited one normal and one abnormal allele for a gene associated with the disorder. A child must inherit two abnormal alleles, one copy from each parent, in order for symptoms to appear.
No test is perfect. Given the probability of erroneous results and the rarity of these mutations, professional societies typically recommend that only prospective parents with a family history of a genetic disorder undergo carrier screening. 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.
Like other home-use tests for medical purposes, the FDA requires the results to be conveyed in a way that consumers can understand and use. This is the same approach the FDA has taken with other over-the-counter consumer products such as pregnancy, cholesterol and HIV tests for home use.
While the FDA is not limiting who should or should not use these tests, it is requiring that the company explain to the consumer in the product labeling what the results might mean for prospective parents interested in seeing if they carry a genetic disorder.
If sold over the counter, the FDA is also requiring 23andMe to provide information to consumers about how to obtain access to a board-certified clinical molecular geneticist or equivalent to assist in pre- and post-test counseling. 23andMe performed two separate studies to demonstrate that their test is accurate in detecting Bloom syndrome carrier status. One study conducted at two laboratories tested a total of 123 samples, including samples from known carriers of the disease. An additional study evaluated 105 samples at two additional laboratories. Both studies showed equivalent results in detecting carrier status of Bloom syndrome when the same samples were tested.
The company also conducted a usability study with 295 people not familiar with the 23andMe saliva collection device to demonstrate consumers could understand the test instructions and collect an adequate saliva sample.
Finally, the company conducted a user study of 302 randomly recruited participants representing the U.S. general population in age, gender, race and education level to show the test instructions and results were easy to follow and understand.