Holly Becker today (left) and in her 20s (right), when she had cancerCourtesy of Holly Becker / The Atlantic

In 2017, Holly Becker took an AncestryDNA test, and the results, she would only later learn, exactly matched those of a young man in New York. This was strange, but the test was not wrong. She really did have his DNA inside her. Two decades ago, she had undergone an umbilical-cord-blood transplant to treat her non-Hodgkin’s lymphoma. The anonymous donor’s cells became her cells, and they still course through her body today. That is what the AncestryDNA test had picked up.

This Sunday, Becker, now 45, met her donor, Patrick Davey, 25, for the first time, in Chicago. They laughed. They embraced. They told each other their life stories. Theirs is the first public case of a patient meeting their cord-blood donor. For nearly 30 years, donations from infant umbilical-cord blood have been strictly anonymous for ethical reasons, but mail-in DNA tests have now introduced a way to circumvent the policy—even inadvertently, as in Becker’s case.

“We just didn’t think technology like this would exist and this scenario would arrive,” says Joanne Kurtzberg, the director of the Carolinas Cord Blood Bank and a pioneer in cord-blood banking. But now it has, and Kurtzberg said it was sure to come up at a cord-blood meeting she happens to be organizing in Miami this weekend.

Becker and Davey’s connection began 25 years ago, shortly after he was born. His mom agreed to donate his umbilical-cord blood, and for several years his cells lay frozen in a cord-blood bank in New York. Meanwhile, hundreds of miles away in Chicago, a 24-year-old Becker started getting fevers and night sweats and extreme fatigue—symptoms, it turned out, of non-Hodgkin’s lymphoma, a cancer that affects white blood cells. She went through multiple rounds of chemo. They all failed. “I was literally at the point where I was about to die,” she says. That’s when her doctor suggested a then-novel transplant involving cord blood from a stranger.

Umbilical cords are rich in hematopoietic stem cells, which ultimately give rise to all different types of blood cells. To do the transplant, doctors would destroy Becker’s own cancerous cells before infusing her with hematopoietic stem cells from a healthy matched donor. Those cells would eventually divide to replace all the blood in her. It was a grueling procedure, and Becker did not fully recover for two years. But she has stayed healthy ever since, and she has always wondered over the years about the anonymous donor who saved her life. Her doctor told her the donor was untraceable. That’s how it’s supposed to work.

Dania Davey with a two-month-old Patrick (Courtesy of Dania Davey)

And when Becker finally spit into a tube for her AncestryDNA test, she was not trying to find her donor; she did not even know that was possible. She was just interested in her family history. But the test matched her to Patrick’s mom, Dania Davey, who immediately messaged Becker when she saw a new and very close match—so close as to be mother or daughter. Davey, who is adopted, had recently found her birth family through AncestryDNA, and this new match made no sense. She knew her birth mother. She certainly knew Becker was not her daughter. They both thought the test was wrong.

But Becker wondered about the transplant. She asked Davey whether she was from New York—because that was the only fact she knew about her cord-blood donor. Davey said yes. When Becker shared her hypothesis with her oncologist at Loyola Medicine, Patrick Stiff, he was initially skeptical. Transplants with hematopoietic stem cells—which can come from cord blood, as in Becker’s case, or from bone marrow—should only alter the blood cells in her body. The rest of her would still be her. Why would DNA in Becker’s saliva match her donor’s? (On the other hand, blood transfusions do not involve killing off the recipient’s blood cells and have only tiny, transient effects on the recipient’s DNA.)

Then, Stiff told me, he heard from yet another transplant patient, who spit into an AncestryDNA tube and got strange results. The DNA in saliva, it turns out, can come from cells in the cheek lining (which should have the recipient’s DNA) and from white blood cells (which should have the donor’s DNA) that guard against bacteria in the mouth. AncestryDNA and 23andMe actually advise customers who have had bone-marrow or cord-blood transplants against taking their tests, as the mix of genetic material can cause them to fail. Often enough, though, the tests return the genetic results of the donor. Many bone-marrow recipients have gotten their donors’ DNA results, and Stiff said he knew of at least one other unpublicized case of a cord-blood recipient who found their donor.

To confirm what everyone now suspected, Patrick Davey took a DNA test. He did, in fact, match the original records for Becker’s anonymous donor. So for all these years, the two strangers had had this unusual bond: To receive cord blood is to carry forever someone else’s DNA inside you. To donate cord blood is to possibly have someone out there—unbeknownst to you even—walking around with your DNA inside them. Davey says his friends joked that he could be pinned for a crime, and he laughed at the absurdity of the idea. He and Becker have vowed to keep in touch. “She’s like family now,” he says.

As far-fetched as that may sound, something like it has happened before. In 2005, forensic scientists reported on a case in Alaska where DNA evidence from a sexual assault pointed to a man who was in jail at the time of the crime. The evidence turned out to have come from his brother, who had given the incarcerated man a bone-marrow transplant years earlier.

Adult bone-marrow and infant cord-blood donations differ in one important way, though. An infant is rarely aware that the cord blood was donated. Patrick didn’t know until the whole business with the DNA test came up. He wasn’t the one who consented to the donation, after all, as he had just been born. His mom did.

This is what gave pause to Brianne Kirkpatrick, a genetic counselor who has written about DNA tests and bone-marrow transplants. “It was a great story, a really happy outcome for the woman. Her life was saved,” she says. “It’s more the implications of what that means on a grander societal level.” Consumer DNA tests have been used to uncover family secrets and track down criminals; those investigations can go very wrong if test results are misinterpreted because some people don’t realize their cord blood was donated.

The cord-blood community is taking seriously the implications of donor and recipient contact too. Kurtzberg says banks had established a policy of strict anonymity in part because of the fear that sick recipients might try to contact donors to get more cells. (Blood from a single umbilical cord may not contain enough cells for an adult. Moreover, siblings of the donor may match the recipient as well.) Nobody wanted a scenario of a dying patient begging a parent to let them take bone marrow from a young child.

This wall has stayed in place, even as the first infants whose cord blood was donated have become adults. Donna Regan, the director of customer-ready products for Be the Match—the nonprofit that operates the registry for cord-blood donations—says her organization recently reviewed the policy about letting recipients contact now-adult donors. The group decided against it—because the mothers had been promised anonymity when they consented all those years ago. “We’ve been very rigid in protecting the confidentiality and identity of cord-blood donors,” says Regan, and she doesn’t expect that policy to change. For new cord-blood donors in the future, Kurtzberg says she thinks banks will have to change what they say about anonymity when asking for informed consent. But that overhaul will be slow.

Sperm banks are currently dealing with a similar fallout, as donor-conceived people are finding their sometimes reluctant donors through DNA tests. Anonymity has allowed tissue banking to sidestep some of the messy questions about life and death. Anonymity will not do so any longer.

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