Home genetic tests reveal origins better than disease risk

In 2019, more than 25 million people ordered home genetic tests to answer one of two questions: “Where did I come from?” or “What diseases am I more likely to acquire?” You can find out just by swabbing the inside of your cheek with a cotton-tipped applicator and sending it to a company that will analyze your cells.

Before doing so, however, ask yourself a question: what are the risks and benefits of ordering a home genetic test?

All people are naturally curious about where they came from, and tests costing under $100 can tell them. Each human cell contains long sequences of the four-letter DNA alphabet that tells our cells how to make proteins and other products that comprise our bodies. Although 99.9 percent of our DNA sequence is shared with the person next to us, the minor differences reveal where our ancestors lived.

Scientists can figure out where we came from by testing people whose ancestors have lived in the same region for many generations. Then, they can compare our DNA patterns to someone unsure of their origins. The bigger a database a testing company has, the more precise the results will be.

The best companies can narrow down your ancestry to any of more than 20 parts of the world. Currently, results for European descendants get narrowed down to the smallest regions because genealogical databases hold more descendants from Europe than from other regions.

According to Providence College biologist and moral theologian Fr. Nicanor Austriaco, O.P., there is no moral problem with ordering an ancestry test. However, ordering the home genetic tests that look for increased susceptibility to diseases is another matter. As Fr. Nicanor has said, companies can provide a report that reveals increased risks for certain diseases, but those reports provide no context or counseling. Recipients often worry intensely — and unnecessarily — over the results.

Genetic tests for diseases are best performed through a physician’s office when you or your family has a medical history that suggests a need for testing. For example, if many family members have had breast cancer, ordering a BRCA test for breast cancer susceptibility may be warranted. The ordering physician will interpret the results and later advise behavior changes, treatment, or closer monitoring based on those results.

There is no advantage to ordering home genetic tests for disease risk. You may, however, gain insight and enjoyment from learning more about your ancestry. If you order an ancestry test, do your research online first. Most companies have stringent privacy guidelines because they realize that their reputation with consumers depends on keeping their customers’ genomes and data private.

DR. THOMAS W. MCGOVERN, a member of Legatus’ Fort Wayne (IN) Chapter, is a Mohs and reconstructive surgeon for skin cancer and co-host of the EWTN Doctor, Doctor radio show and podcast.