DNA Testing Unlocks Secrets But Leaves Footprints

DNA tests are to 2018 what the iPhone was to 2007: a game-changing technology poised to reshape how we see ourselves and live our lives. So-called direct-to-consumer DNA testing companies like 23andMe, Ancestry and Helix advertise the ability to reveal your ancestry, inform you of your health status, and even guide you on how to exercise and eat -- all for $200 or less. Recent headlines have highlighted the role of the personal genomics revolution in solving crimes. Once your genetic information is out in the world, it can be hard to control how it is used.

A little bit of saliva can go a long way. The tests are nearly 100 percent accurate when it comes to telling you who you’re related to. DNA is great at identifying familial relationships like parents, grandparents, aunts, uncles and even second and third cousins. Beyond that, it gets fuzzy. A test by 23andMe Inc. can identify whether you might carry a marker for a certain genetic disease, but that doesn’t necessarily mean you’ll wind up developing it. And tests that claim to extract from your genome insights to improve your beauty, diet and fitness regimen are even less useful. In most cases, the science isn’t developed enough to tell you, say, how to maximize your workout routine based on your genetics.