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Except in such clearly defined cases, physicians and the medical systems in which they work have been hesitant to adopt any of these genetic tests for the wider patient population because of doubts about their usefulness. Kaiser Permanente, known for its cost-consciousness as well as its attention to evidence-based medicine, was one of the first to embrace broad-based carrier screening for cystic fibrosis. But geneticist Witt, who led that effort, says the system is very cautious about predictive genetic tests. For him, the added expense takes a back seat to concerns about inconclusive results that have no true clinical interpretation and can even be misleading. “Our guiding principle is doing what’s best in terms of medical care,” Witt says.
Even though some gene variants have been strongly associated with disease, that genotype alone may not be sensitive or specific enough to warrant diagnostic or predictive use. One can go online and order a $280 test for APOE4 to check for susceptibility to Alzheimer’s disease, for instance, but the American College of Medical Genetics has recommended against using it for that purpose. Not having the gene doesn’t mean a person is safe from the disease, and so far, there is no means of protection or treatment for someone at risk. “Among genetics folks that test died out quickly,” Witt recalls.
About half of U.S. states permit direct-to-consumer genetic testing. In an alert last summer about at-home genotyping, the Federal Trade Commission (FTC) told consumers: “A healthy dose of skepticism may be the best prescription.” Some of the tests lack scientific validity, the agency said, and others provide results that have meaning only in the context of a medical evaluation. In urging consumers to be wary, the FTC called upon the authority of the FDA and the Centers for Disease Control. Neither agency, it said, is aware of valid studies that prove tests like the one for Alzheimer’s give accurate results, or that genetic studies can be used effectively to recommend nutritional choices or predict someone’s ability to withstand environmental toxins.
Such clear disapproval might seem a pathway to stronger regulation. But the FDA doesn’t review laboratory-developed tests, only commercial “test kits” that are sold to other labs or clinics. Aside from this, the agency has proposed to review only a sub-category of complex molecular prognostic tests for clinical accuracy. In February it announced its first approval, for a test called Mammaprint by Dutch company Agendia that predicts breast cancer recurrence risk.
The Centers for Medicare and Medicaid Services (CMS), which certifies labs to perform clinical tests, declined in August to require regular checks on lab proficiency, citing cost. In its petition asking for such federal review, the Genetics & Public Policy Center in Washington, D.C., cited several examples of mistakes in genetic tests. In one case, a lab gave a clean bill of health to close relatives of a man with a fatal, late-onset neurological disorder. After the lab realized that it had tested the wrong mutation, it conducted a retest and found that one relative did have a mutation that led to disease.
Most people mistakenly believe that the federal government already regulates the validity and quality of all types of genetic tests. In fact, quality testing is voluntary for most of them. Last year, two U.S. Senate bills were introduced to increase oversight of laboratories in this area, but neither made it out of committee. One, by Senator Edward Kennedy (D-Massachusetts), would categorize all laboratory-developed tests as medical devices and require evidence of clinical validity as well as proficiency testing —with special scrutiny given to DTC genetic tests. “Payers certainly want to know,” says Gail Javitt, law and policy director for the Genetics & Public Policy Center. “Does the gene have something to do with disease or not?”
Online companies often advertise the ability of consumers to manage their own genetic information and keep it private. But once a patient discloses the news to a family physician, it will likely become a notation on his or her medical record. DNADirect explains that it identifies test results only by number, also advising clients to secure insurance before taking a test. Under the Health Insurance Portability and Accountability Act, predictive genetic information cannot be considered a preexisting condition. At the same time, if they hide genetic test results from an insurer at any time, consumers can lose coverage entirely. There are no clear safeguards, either, that limit ways in which the companies themselves might store or use the DNA collected or related information. The Genetic Information Nondiscrimination Act passed the U.S. House of Representatives by an overwhelming majority last spring but must be approved by the Senate and signed into law.
