Direct-to-consumer Genetic Testing: Considering the Benefits and Limitations of Genetic Testing in your Personal Health Care Routine

Genetic Testing Blog Picture — An example of results of DNA sequencing used in genetic testing (source).

If someone told you that you could learn about your chances to developing certain diseases, like cancer or Alzheimer’s – would you? As a result of advances in scientific technology, private companies are now offering genetic testing kits to consumers that provide insight into their own genetic make-up. People are often drawn to these tests as they claim to provide information related to risks of developing some forms of cancer, personal responses to medications, and other health information. Before purchasing such a test, it is important understand the facts and know what you can really gain from the results.

1) What is direct-to-consumer genetic testing?

Direct-to-consumer genetic testing is a type of genetic test marketed to consumers that provides access to individuals’ genetic information. Currently, these genetic tests are advertised to identify your response to medications, your ancestry, and of greatest interest, the risks of developing certain diseases such as Alzheimer’s, diabetes, and various types of cancer, such as breast. This type of test often does not involve a doctor or medical professional. This is in stark contrast to traditional genetic tests that are only available through healthcare providers, who order them for specific conditions, and interpret the results. With direct-to-consumer genetic tests, anyone can purchase a genetic test and have it mailed directly to their house. Consumers collect their own DNA sample at home, often by swabbing the inside of a cheek or spitting into a test tube, and then mailing it to a laboratory. Test results are delivered by mail or posted online. The price for at-home genetic testing ranges from a few hundred to thousands of dollars.

2) What are the benefits of direct-to-consumer genetic testing?

With direct-to-consumer genetic testing gaining popularity, one clear benefit is that people can be more proactive in their personal health care. Additionally, there is greater awareness of how genetics may factor into certain diseases, and the tests do offer the benefit of learning about ancestral origins.

3) What are the limitations of direct-to-consumer genetic tests?

Direct-to-consumer genetic testing has fairly significant limitations. One critical issue is that without guidance from healthcare providers, consumers may not be able to effectively interpret information from these tests, leading to inaccurate, incomplete or misunderstood assumptions about their health. Even if the results were to be brought to a health care provider, they may not be able to analyze the data properly as most companies do not provide critical information, such as the accuracy of the results, for example, what research they used to determine whether your genetic sequence correlates to disease¹. The vast majority of diseases tested for, such as cancer, involve a complex relationship between genes, lifestyle and environment that is yet to be fully understood. Therefore, receiving a result of an increased genetic risk for diseases like cancer is not a reliable indicator of whether you will or will not develop the disease. Ultimately, more research is needed to fully understand the benefits and limitations of direct-to-consumer genetic testing.

Additionally, consumers should be aware of how their genetic information will be stored and used after the testing is done. Although some consumers may want to contribute to science and choose to share health information that be can be used to make new discoveries, they should research how their genetic privacy will be protected to ensure their genetic information is not used in an unauthorized manner. In Canada, currently there are no laws preventing insurance companies from discriminating against people with increased genetic risk of disease. If a consumer’s genetic information is not kept private, it could potentially hurt their chance of obtaining life or health insurance².

4) Should I use direct-to-consumer genetic testing in my healthcare routine?

In its current state, direct-to-consumer genetic testing has limited power to accurately predict future disease. It cannot adequately calculate an individual’s risk of developing complex diseases such as cancer as there is a complex relationship between genes, lifestyle and environment that lead to development of the disease. If you have a strong family history of certain cancers, such as breast cancer, it is best to talk to your health care provider. Genetic testing can be an exciting and novel tool to learn more about your ancestry and personal traits. However, genetics is only one of many factors contributing to an individual’s health. Environmental and lifestyle factors can also contribute to a person’s risk of developing many diseases, including cancer. As I mentioned above, these issues are best discussed with your healthcare provider, along with your family history, to gain a more complete picture of your health that cannot be addressed through direct-to-consumer genetic testing.

This article was written by Dr. Katherine Wright. Katherine finished her PhD at the University of Toronto in 2014, where she studied how breast cancer spreads from one part of the body to another, a process known as metastasis. To learn more about Katie and her research check out our members page.

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