Cancer Treatment Centers of America

The limitations of at-home genetic tests

CTCA

Genetic test

Perhaps you want to learn more about your family’s ancestry. You may also be interested in family traits you may have inherited. Or maybe you want to find out about your risk for developing certain diseases. If these or other curiosities have you looking to test your genetic tree in a quick and convenient way, a new federally approved option may have caught your eye.

New direct-to-consumer (DTC) genetic tests, like the one approved in April by the U.S. Federal Drug Administration (FDA), are seen by some as tools that allow everyday Americans to learn not just about their family lineage but also their risk for diseases ranging from late-onset Alzheimer’s to Parkinson’s, all from the comfort of home. The news may sound like a welcome development to many, but experts warn that these at-home tests should be viewed with caution.  

For several years prior to the FDA’s April announcement, genetic testing for hereditary risk could only be performed in a clinical setting by medical professionals testing patients for inherited diseases and genetic mutations, such as in the BRCA genes, which increase the risk for developing breast and ovarian cancers. Often, patients were required to see a genetic counselor before getting tested. The results were then shared with a doctor, who helped guide any medical decisions that resulted from the findings.

Now, the new DTC genetic tests put the results directly in the hands of the consumer, much like the information you get from insulin, home pregnancy or HIV tests. Rather than the news coming from a trained medical professional, these at-home test companies share the results with the consumer through their websites, by mail or over the phone—without a doctor’s order or guidance from a physician or genetic counselor. That concerns the American College of Medical Genetics and Genomics, which insists that medical professionals trained in genetics should be the ones to interpret and deliver genetic results, while also taking into account the patient’s family and medical history for fuller context.

“Cancer genetic counselors review personal and family histories, assess the chances of an inherited risk for cancer, and educate people about cancer, genetics and genetic testing,” says Eric Fowler, Genetic Counselor at our hospital near Chicago. “When genetic testing is offered, genetic counselors empower people to make informed decisions about whether to have testing, and ensure appropriate and accurate tests are ordered. These genetic test results are interpreted in the context of the personal and family history, are explained in detail and their impact on medical management carefully considered.”

As easy as the DTC genetic tests may be to use—typically requiring the user to simply deposit saliva in a small tube—genetics is a far more complicated field of study than a take-at-home test may suggest. Many genetic tests cannot predict for sure whether someone will develop a specific disease. Rather, they are designed to detect variations in certain genes to gauge the person’s level of risk—information he or she may use to decide, with a medical professional’s guidance, whether to pursue more regular screenings, or even aggressive preventative measures like prophylactic surgeries. Some experts are concerned consumers will use the information they glean from at-home tests to make important health-related decisions without the benefit of medical advice, and without understanding that sometimes, the results may be inaccurate.

Against that backdrop, the FDA’s decision to approve the DTC tests came with caveats: “Results obtained from the tests should not be used for diagnosis or to inform treatment decisions,” the agency said in a statement, adding that false positive and false negative findings are also possible.

“Direct-to-consumer genetic tests vary greatly in terms of their usefulness and reliability,” says Fowler. “While DTC tests may report the chances of developing certain health conditions, or information about the genetic code, results do not always speak to overall risks. The quality and accuracy of DTC testing are hard to measure without knowledge of genetics, genetic testing methods and laboratory certifications.”

In fact, the FDA warns that results from these tests should not be considered diagnostic, and should not inform any kind of treatment plan. Consumers are advised to seek out genetic counselors if they have questions. “Genetic tests done through DTC labs that provide information on risks that affect health and the chances of having children with genetic conditions may not be as thorough as what would be ordered through a genetic counselor or physician,” says Fowler. “Results that address health and risks should be interpreted with caution, and questions reviewed with a genetic counselor.”

Learn more about genetic testing and cancer.