Commercially available DNA testing services are connecting people to branches of their family tree that may have gone undiscovered in years past. High-profile cases have landed on TV shows like the PBS program “Finding Your Roots.” Investigators in the Golden State Killer case used forensic genealogy and a commercial testing service to track down relatives of the suspect. But what are the risks of using these services?

The UC Davis Humanities Institute and Davis Science Cafe are co-hosting a public discussion titled “Who Are You? The Promises, Pitfalls, and Social Risks of DNA Testing” on Wednesday, April 24 at Davis Odd Fellows starting at 5:30 p.m. (Seating is limited, and you can RSVP here.)

UC Davis Professors Graham Coop and Meaghan O’Keefe gave Insight a preview of the lecture. Here are three things they shared that you should know about DNA testing.

Don’t confuse your genetic ancestry with your identity.

Coop: These companies are incredibly popular, and around 26 million people have done them so far. And a lot of people are finding out interesting things about their family history. They're finding out about relatives they've never known they had, they're finding out something interesting about their ancestry, and that's all well and good.

But the issue is that people can mistake their genetic ancestry for their cultural ancestry. And so there's a risk that people sort of confuse what they know about their family history with some deeper ideas about who they are. And so that's a real concern.

O’Keefe: I think two areas that are particularly troubling are these questions of identity, that somehow we think that if we know our genetic code, it says something essential and unchangeable about us. That there's a kind of determinism to it. And I think in some ways this sort of discourages people from changing the things they can change in terms of health and that sort of thing. And at sort of the uglier end of it, it can mean that people have deterministic ideas about particular groups of people and that this can reinforce stereotypes and prejudices and that sort of thing.

Be aware of biases within the databases.

Coop: The databases that these companies have are large, but they are biased in certain directions towards people of European ancestry. And so people of European ancestry can get potentially quite high-resolution looks at where they come from, but people from elsewhere in the world can often get a far blurrier picture and sometimes incorrect picture.

O’Keefe: I think one interesting example about this is people of African descent in the United States who want to trace their ancestry because this is something that has been denied them, sort of an entire history kind of ripped away from people, and there are some testing organizations that concentrate on African ancestry, but we still have the problem that there aren't enough samples from Africa. And it's a big place, and it is incredibly genetically diverse. So you're not going to get the same kind of rich picture. And ironically for those people who don't have access to the same kinds of geology records that, say, people of white European ancestry do in the United States.

Keep in mind who could have access to your DNA, including law enforcement.

O’Keefe: In terms of privacy, this is a real concern that law enforcement agencies may have access to some of these DNA profiles. And it depends on which company you use and whether you agree to participate in research, whether or not your DNA will be searchable. For instance, on 23 and Me, if you check that you want to participate in research, then you're protected under HIPAA, the patient privacy act. But on the other hand, you're also handing over your DNA and your genetic profile to a company for them to do with with it what they please. And I think that may be a concern for some of us.

Coop: The first thing to say, as Megan pointed out, is if your data is in 23 and Me and Ancestry, the police would have a lot of difficulty getting access to that information. But there are other services, such as GEDMatch where people have voluntarily uploaded their DNA to look for family tree matches to learn more about themselves, and those services, the access to those are far easier. And that is indeed what the law enforcement did to trace the Golden State Killer. The access to that is fairly open and at the moment I think there's relatively few limits on how such searches can be performed.