Since the human genome was completely sequenced in 2003, genetic testing has exploded into a multibillion-dollar industry. And with the rise of so-called “direct-to-consumer” tests such as those sold by 23andMe, which don’t require a physician’s sign-off, investigating your genes is easier than ever. But depending on your reasons, taking one of these tests may not be right for you, says Kathryn Phillips, PhD, a UCSF professor of clinical pharmacy who studies the use and value of new technologies for improving health care. She explains what you need to know before sending away your DNA.
What will you learn from a direct-to-consumer genetic test?
Many of these tests are geared more toward entertainment than clinical use. They report heritable traits like cheek dimples, earlobe type, and eye color, which may be fun but are not clinically important. They can also offer clues about disease risk, but such information is just a starting point. A physician would need to order you a more comprehensive, clinical-grade test if you want medical care based on your genetics.
How does a direct-to-consumer test compare to a clinical test?
Direct-to-consumer kits typically aren’t testing at the same depth as clinical-grade tests. Take BRCA mutations, for instance. These are variants of the BRCA genes that may predispose a woman to breast or ovarian cancer. Direct-to-consumer kits only test for some of the most common mutations, so they can’t tell you whether you’re in the clear for every possible BRCA mutation. You’d need a clinical test for that.
What should you do if the results are unsettling?
Knowing what to do with a potentially confusing or unsettling finding can be a challenge. Imagine, for example, you tested positive for a gene that increased your risk of a disease for which there currently is no cure, such as Alzheimer’s. A genetic counselor could help you navigate results like that. The good news is that for most health conditions, genetics is just one piece of your risk: Your genes aren’t the only factor determining whether you get sick.