5 Things to Know About DNA Tests

5 Things to Know About DNA Tests

January 27, 2021
Shari Steinbach

By Shari Steinbach, MS RDN, RDBA Contributing Editor

The landscape of genetic testing has changed dramatically in recent years and there are now hundreds of companies offering direct-to-consumer (DTC) tests. These kits include reproductive, predictive and diagnostic tests that provide information on ancestry, lifestyle factors and potential disease risk. With interest in these tests growing and the field of genomics changing rapidly, it’s important for retail health professionals to have an understanding of DNA tests to provide accurate information to consumers. Here are 5 key things you should know:

  1. How tests work – A DNA test kit will include items for collecting DNA, such as a swab to collect cells from the inside of cheeks. The customer then sends the kit off to a lab, where scientists isolate their cells and a laboratory will analyze the sample to look for particular genetic variations. The variations included in the test depend on the purpose of the test. This guide can help individuals navigate the many tests available.
  2. Privacy implications – DNA is basically an individual’s source code. If DNA testing companies are sharing codes it can be a bit disturbing. Get a clear picture of what the company does with testing results and if users can authorize any sharing or not.  With cyber-attacks happening quite regularly, it’s also important to ask about the measures the DNA testing provider has in place to prevent hacking into information. In 2018, this happened to the company MyHeritage.
  3. Testing kit accuracy can vary – While some tests have a high level of accuracy with the testing methods used, not all tests meet the same standards. It's also worth noting that no matter how many variants a kit tests for, it can't predict complex traits like intelligence, which are influenced by many different genes and environmental factors. Caution should also be used with using companies that offer predictions about optimal diets, what sports you'll excel at, and other questionable tips. Experts say using DNA tests to infer this type information is at best premature and at worst pseudoscience.
  4. There are advantages and disadvantages – DTC genetic testing provides consumers with the opportunity to learn about their genetic profiles related to phenotypes of interest in a convenient and less expensive manner. If a consumer has a genetic predisposition to a certain disease then he or she may take proactive steps to improve his or her own health. Results, however, may include unexpected information about disease risk without any context or guidance. Also, diseases are generally affected by many genetic factors along with environmental and lifestyle influences such as age, sex, race, nutrition, exercise, and stress. Thus, DTC genetic testing only indicates that one has a genetic propensity for that disease. 
  5. Using the results - Just as experts recommend seeking advice from a genetic counselor prior to testing, it is probably more important to have a health professional weigh in once the results are back. They can help individuals interpret the implications of their genetic risk, understand what can be done to prevent or monitor for early signs of a disease, and how to discuss results with relatives who have similar DNA.