A Woman’s AncestryDNA Test Revealed a Medical Secret

When Holly Becker was in her twenties, she was treated for non-Hodgkin’s lymphoma by undergoing an umbilical-cord-blood transplant. For ethical reasons, donations from infant umbilical-cord blood have been strictly anonymous for almost 30 years. But Becker, using the mail-in DNA test provided by AncestryDNA, discovered that the cells of the donor from two decades are still within her when her results exactly matched those of a young man in New York, and she was able to meet him.

After numerous rounds of chemo that ultimately failed, Becker was near death when her doctor suggested the then-novel procedure of transplanting cord blood from a stranger. Doctors would destroy Becker’s own cancerous cells before infusing her with hematopoietic stem cells – which are plentiful in cord blood – from a healthy matched donor. Those cells would eventually divide to replace all the blood in her, and Becker did not recover entirely from the grueling procedure for two years. But she stayed healthy, and she always wondered whose blood saved her life.

Becker was not trying to find the anonymous donor when she used the DNA kit. She was just curious about her family history. But she matched to her donor’s mother, Dania Davey, as if she was indeed was Davey’s daughter. They both thought it was mistake by the company. After some research and another patient of Becker’s oncologist getting odd results from AncestryDNA, they discovered the truth. The DNA in saliva, it turns out, can come from white blood cells (which should have the donor’s DNA) that guard against bacteria in the mouth. In fact, many mail-in DNA test companies advice against patients that have undergone bone-marrow or cord-blood transplants against taking their tests, as the mix of genetic material can cause them to fail. Or, the test could pinpoint the donor’s DNA.

To prove their hypothesis, Davey’s 25-year-old son, Patrick, took a test. And he matched the original records for Becker’s anonymous donor, and Dania had in fact donated his cord blood when he was an infant. For more than two decades, Becker had carried Patrick’s DNA inside of her.

See Sarah Zhang, A Woman’s AncestryDNA Test Revealed a Medical Secret, The Atlantic, September 13, 2019.

Special thanks to Laura Galvan (Attorney, San Antonio, Texas) for bringing this article to my attention.