By Kevin E. Noonan --
Last Thursday the genetic diagnostic and DNA analysis company 23andMe announced that the FDA had granted the company approval to market a genetic diagnostic test for Bloom's Syndrome, the first such approval for this rare genetic disease. The news is tempered by the company's further announcement that it will not offer the test to consumers "until it completes the regulatory process for additional test reports and can offer a more comprehensive product offering."
Readers may recall that the FDA effectively stopped 23andMe from selling its genetic analysis kit, which the company marketed as Personal Genomic Services (PGS) in November 2013 by issuing a Warning Letter to the Company (see "FDA Threatens Agency Action Against 23andMe Over Personal Genetic Testing"). According to the FDA, genetic diagnostics assays fall under the agency's purview and authority because they are medical devices (21 U.S.C. § 321(h)). According to the letter, the testing service offered "is intended for use in the diagnosis of disease or other conditions or in the cure, mitigation, treatment, or prevention of disease, or is intended to affect the structure or function of the body." At that time, the agency professed a desire to work with the company to assist in developing the type and quantity of evidence required for approval, but warned that it had spent "significant time" evaluating the PGS test and providing feedback to 23andMe. It appears that the company complied with the agency by submitting the evidence for approval of a much more limited test (i.e., limited to Bloom's Syndrome), compare to the tests offered previously (which included more that 250 "diseases and conditions" such as BRCA gene mutations, diabetes, coronary artery disease, an sensitivities to drugs such as warfarin, clopidigrel and 5-fluorouracil).
The test is described as a "spit test kit and a chip array platform," and approval is limited at this time to detecting genetic markers for Bloom's syndrome. Bloom's syndrome is a genetic disease inherited in an autosomal recessive manner, that predisposes individuals to certain cancers and is also associated with short stature, sensitivity to sunlight exposure and shortened lifespan. The locus of the mutation is in the BLM gene on chromosome 15 (at 15q26.1) and encodes a DNA helicase. Defects in this gene cause a dramatic (~ten-fold) increase in homologous recombination in cells from affected individuals, resulting in genomic instability. Genetic testing is the only way to predict risk for passing the disease to offspring, as parents having only one copy of the gene show no symptoms.
The FDA's decision to permit 23andMe to offer the test, while important to the company and to those individuals who may be at risk for passing on the Bloom's syndrome trait to their children, is also significant for the type of testing the FDA required and the evidence it mandated for approval. For example, 23andMe in an announcement stated that it "conducted extensive comprehension studies with consumers from different backgrounds, education levels and incomes," as well as test accuracy and validity.
The company's future in the genetic diagnostics space remains uncertain, however, in view of the following disclaimer on its website:
Updated February 19, 2015b: 23andMe provides ancestry-related genetic reports and uninterpreted raw genetic data only. We intend to add some health-related genetic reports in the future once we have a comprehensive product offering. At this time, we do not know which health reports might be available or when they might be available.
A disturbing note was struck by Alberto Guitierrez, Director of the Office of In Vitro Diagnostics and Radiologic Health in the agency's Center for Devices and Radiologic Health, who stated that "[t]he 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," and that the FDA intended to "exempt these devices from FDA premarket review." How disturbing this sentiment may be will depend on how widespread access to genetic testing becomes and the extent to which providers such as 23andMe provide information to consumers receiving this information; indeed, the company's disclaimer suggests that FDA action has encouraged it not to provide any interpretation for the "raw genetic data" it supplies to consumers. For all the criticism that has been leveled against Myriad (some of which may have been justified) the company acted responsibly by ensuring that its customers had access to genetic counselors who explained the significance of their test results and provided options for accommodating the consequences of any propensities their genetics disclosed. Among all the negative press Myriad received there were two types of stories that did not appear: one, that the company had provided a misdiagnosis (of either type); and two, that someone had decided to end their life because they misinterpreted the results of their test or its implications on their health. Minimizing the risk of the latter outcome will depend even more heavily on adequate counseling as more individuals have more tests for more genetic diseases, particularly as those diseases expand to include those that are less determinative than tests like the BRCA test or 23andMe's Bloom's Syndrome test and as there are more opportunities for behavioral modifications that could modulate patient outcomes. Mr. Gutierrez is also reported to have said that authorization of 23andMe's test "supports innovation and will ultimately benefit consumers." But that innovation will be costly if it is not accompanied by the appropriate amount of interpretation so individuals can make the best-informed choices for themselves.