The Bookshelf

Ancestry DNA testing – a risky business

Strands of DNA under a microscope

If you’re thinking of making a bespoke book about your family, you might be thinking of doing an ancestral DNA test. It sounds like such a fun idea: an easy test that can tell you if you had Neanderthal ancestors, or if your unusual eye colour came from long-lost family in the Mediterranean. However, privacy experts say you should be cautious.

The problem is when you send away a tube of your spit or a cheek swab, you are giving away your full genetic code. Every cell on that swab carries the full sequence of your DNA, including the mutation pattern that makes it uniquely yours. “It’s the most valuable thing you own,” says Peter Pitts of the Center for Medicine in the Public Interest, a nonprofit advocacy group.

Home DNA testing kit in a box
Health information

Legitimate genetic testing companies promise not to sell or give your data away without consent. But usually, a broad consent is part of the contract you make with a DNA testing company – and we’ve all seen those big, long agreements scrolling by, and are used to just clicking ‘agree’.

Even if you do read the whole agreement, you may not understand what you’re giving the company permission to do, said Hank Greely, director of the Center for Law and the Biosciences at Stanford School of Medicine in the US.

“If you just send your DNA in for genealogical work, those companies typically run a test for hundreds of thousands of genetic markers, even though they may be only looking for a couple of hundred markers,” Greely said. You may only be looking for information about your great-great grandfather, but the company’s analysis shows important things about your health too. 

DNA test tube and marker readout

“The company never told you because that is not the business they are in,” he said. “They are in the genealogy business.”And for many of us, there really are scary things in our genomes, he said.

That information may or may not be useful to someone else.

“Maybe you’re doing it for fun or for laughs or for conversation at the dinner table but at the end of the day the company now can sell that information 100 different ways,” said Pitts.

Hands holding a strand of DNA
Danger of hacking

Your DNA can also be used to identify you. In 2013, a team at the Whitehead Institute for Biomedical Research figured out the identities of 50 people from DNA donated anonymously, using easily available internet databases. That’s why companies do their best to strip away personal information from the genetic codes, but anyone who has been the victim of credit card fraud or identity theft knows anonymising data is not foolproof.

“You cannot promise people absolute confidentiality,” Greely said. “It’s possible somebody will hack into a company database that does contain your information. My financial information has been hacked three times in two years. All that stuff is out there.”

What’s the lesson here? Do your research, read the agreement clauses carefully and think about whether it’s worth it to find out more about your ancestors, given the significant risks to your privacy.

Thanks to nbcnews for the information in this post.