Genetic testing is all over the news these days.
In fact, if you Google “genetic test,” you get 215 million results in less than a second.
Whether it’s for ancestry, preventative medicine, or pharmacogenomics, different types of genetic tests are vying for the attention of consumers and clinicians. The American Medical Association (AMA) states that “thousands of genetic tests are available to aid physicians in the diagnosis and therapy of many diseases.”
There are two major types of genetic tests:
- Direct-to-consumer (DTC) tests are just as the name suggests: a consumer can buy these tests over-the-counter, often from retail stores or through the Internet.
- Clinical tests must be ordered by a healthcare provider and are often administered at the clinic, practice, or hospital.
With so many options, how do you know which tests to trust and which one is right for you?
Direct-to-Consumer Genetic Testing
According to the AMA, there are several types of DTC tests to identify disease states, including:
- Carrier testing for diseases such as cystic fibrosis and hemochromatosis
- Testing for predisposition to complex diseases such as hereditary cancers, cardiovascular disease and depression
- Whole exome or genome sequencing
Some of the most popular DTC genetic tests provide insight into ancestry. These genetic tests are typically referred to as “recreational” tests.
Clinical Genetic Testing
There are many different clinical genetic tests, including those developed by our parent company, Myriad Genetics, Inc.
Clinical genetic tests help healthcare providers identify genetic reasons for diseases, differences in how medications are metabolized, genetic alterations causing tumor growth, and many other applications. The findings help inform patient treatment decisions.
FDA Warning on Direct-to-Consumer Pharmacogenomic Tests
Pharmacogenomic (PGx) testing comes in both DTC and clinical forms. Pharmacogenomic tests analyze a person’s DNA to determine how they metabolize or respond to medications. While PGx tests cannot confirm which medications or doses will work for a patient, they can help identify which medications may require dose adjustments, may be less likely to work, or may have an increased risk of side effects based on a patient’s genetic makeup.
The FDA recently warned consumers about relying solely on direct-to-consumer pharmacogenomic tests without the involvement of a healthcare provider.
“Consumers should not use this test to make treatment decisions on their own. Any medical decisions should be made only after discussing the results with a licensed healthcare provider and results have been confirmed using clinical pharmacogenetic testing,” said Tim Stenzel, director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health, in the FDA statement.
Likewise, the American Medical Association warns “the results of genetic tests (whether DTC or ordered by a physician) can be challenging to interpret…AMA policy encourages patients to undergo genetic testing under the guidance of a physician or genetic counselor.”
Clinical Pharmacogenomic Tests
The GeneSight® test is an example of a clinical genetic test that must be ordered by a healthcare provider. Why? Because it is meant to guide physicians’ medication selection.
Healthcare providers use clinical pharmacogenomic tests to help them get a better understanding of what medication might work best based on their patient’s genetic makeup. Since genetic insight is only part of the puzzle, healthcare providers must take into consideration their patient’s entire medical portfolio to determine medication selection. That’s because other factors (like drug/drug interactions, food/drug interactions, and environmental factors such as lifestyle) can influence medication response and susceptibility to side effects.
“Finding the right medication is like looking for a needle in a haystack,” said Holly Johnson, Ph.D., Medical Information Manager, Myriad Neuroscience. “We like to say that clinical pharmacogenomic tests – like the GeneSight test – aren’t able to find the needle for you, but they do remove a lot of the hay.”
If you are interested in learning more, take the next step.