Update 4:25PM ET, July 5th 2018: Today, Secretary of Health and Human Services Alex Azar told reporters that officials will take cheek swabs for DNA testing to reunite parents and children separated at the border, according to NBC News. HHS did not reply immediately to an emailed inquiry about who will be conducting the DNA tests.

More than 2,000 children have been separated from their parents at the US border as a result of the White House’s new “zero tolerance” policy, and immigration agencies seem to have no clear plan for reuniting them. In one case, a six-year-old’s ability to remember her aunt’s phone number became her only lifeline to her family. “Most children here aren’t able to give names, much less a phone number,” an official told ProPublica. With children less than a year old lost in the system, it’s become heartbreakingly difficult to simply match children to the parents that brought them.

In the midst of the crisis, consumer DNA companies offered their services as an unlikely solution. After a nudge from a member of Congress, 23andMe has offered to donate DNA kits and other resources, using spit samples to help parents find missing children in the bureaucratic maze. MyHeritage made a similar offer, promising that the tests will be processed within the company and not shared with third parties. “We’re calling upon relevant government agencies to help us with facilitating this,” a MyHeritage spokesperson told The Verge. “We’ll work with anyone to get the kits to the right people.”

It’s inspiring to see the massive outreach around helping these families. 23andMe has offered to donate kits and resources to do the genetic testing to help reconnect children with their parents. We are waiting to see the best way to follow up and make it happen. — Anne Wojcicki (@annewoj23) June 22, 2018

The prospect of DNA testing children has been raising concerns among bioethicists ever since the proposal first hit headlines. They worry that the rush toward DNA testing could become a kind of backdoor surveillance technique. “It’s not as simple as just saying, ‘Hey, let’s just use our magic wand of DNA testing, and we’ll put everybody back together again,’” says Arthur Caplan, a bioethics professor at the NYU School of Medicine. “There are challenges.”

“Normally, for a child that age, you would need the consent of the child’s parent.”

The biggest question is whether the children in custody can consent to have their DNA tested. Both 23andMe and MyHeritage require the subject’s consent before a sample can be processed, in accordance with broader medical ethics rules. For children under 18, consent must be obtained from a legal guardian, but this situation makes that impossible.

“Normally, for a child that age, you would need the consent of the child’s parent,” says Natalie Ram, a professor and bioethics expert at the University of Baltimore’s School of Law. “But here, we can’t do that precisely because we can’t connect the parent and the child.”

Other provisions allow the government to forcibly collect DNA in connection with a felony investigation, but the detained children aren’t being charged with a crime. While their parents face misdemeanor immigration charges, the children are simply treated as unaccompanied minors. Eventually, they may become wards of the state, in which case immigration agents could consent on their behalf, but only after reunification efforts have failed. For children too young to remember their parents’ names or pick them out of a photo array, meaningful consent may simply be impossible.

There are also civil liberties concerns. If the government routinely collected DNA samples from separated parents and children at the border, those same samples could have a significant impact on future immigration proceedings or even criminal cases. Both MyHeritage and 23andMe would keep the data on their own platforms, but it could be vulnerable to future subpoenas from law enforcement. “Letting the Trump administration subpoena a DNA database of immigrants, asylum seekers, and people they’re trying to throw out of the country is probably not consistent with the ethics of the people being tested,” says Caplan.

“What happens to that genetic data once reunification occurs?”

Presented with those concerns, MyHeritage emphasized that the company would perform the testing itself, leaving as little data as possible in government hands. “It would only be a surveillance system if it was the government organizing and having access to the kits, having access to the data,” the spokesperson said. “MyHeritage would process the data, and we wouldn’t share any of it due to the sensitivity of it.” Still, it’s unclear how well such a system would hold up to a court order.

23andMe declined to comment on the bioethics concerns directly, saying only that the program was in “very early stages.”

For many experts, simply retaining the data is too great a risk. “What happens to that genetic data once reunification occurs?” says Ram. “Segregating the profiles from the general consumer database is important. Even more important is destroying both the sample and the data once a match is made and the family is reunified.”

Immigrants to the US will often submit DNA testing to prove familial relationships, but that testing is strictly voluntary. While the United States Citizenship and Immigration Services has lobbied for the power to force genetic testing in cases of suspected fraud, it still can’t compel immigrants who don’t want to be tested. If DNA testing becomes a more routine part of the immigration system, family reunification could be used as a way around that restriction.

Federal agencies already have a number of systems for identifying relatives, most notably the Combined DNA Index System’s missing person’s database, which allows family members to submit DNA to help find a missing relative. Crucially, federal law prohibits using the database in criminal investigations for fear it would discourage relatives from submitting samples. Still, the child separation crisis is not a conventional missing person’s case, and it’s unclear whether it could be used in this instance.

Instead, Caplan suggests setting up a university-based genetic testing outfit supervised by an independent body akin to the National Academy of Medicine, where a board of experts could address questions of privacy and consent. Genetic testing would also have to be accompanied by mandatory counseling, Caplan says, in case the tests turn up unforeseen medical risks or familial complications.

“We shouldn’t forget that it’s absolutely inexcusable that the administration scattered children all over the place and doesn’t have the information at hand to reunite these families,” Caplan says. “And that shouldn’t get lost in the quirky techno issue of ‘can you use genetic testing to reunite them.’ It’s a problem we shouldn’t have.”

This story was originally published June 22nd, 2018, 1:18pm EDT.