The New Yorker:

Through genetic testing, millions of Americans are estimated to have discovered that their parents aren’t who they thought. The news has upended relationships and created a community looking for answers.

By Jennifer Wilson

Lily Wood is forty-three years old but considers April 9, 2019, to be her “rebirth day.” That was the date she received her results from Ancestry, the direct-to-consumer DNA-testing company. A self-described biohacker, Wood had been curious to see whether she had a genetic predisposition to diseases like Alzheimer’s. “I wanted to get ahead of things,” she told me.

It was actually her second time testing. The first time, Wood had used 23andMe, but the results had seemed off to her. “The ethnicity was wrong,” she said, before correcting herself. “I thought it was wrong.” Her heritage, as she’d always understood it, was French on her father’s side and Norwegian on her mother’s. And yet the 23andMe customers who had come up as genetically close matches had Italian names. Wood, who lives in Minneapolis, where she grew up, called her sister, who speculated that a strand of hair belonging to a lab technician had gotten into the vial. Her sister advised her to try Ancestry. When the new results came in, Wood learned that there was a man in the company’s database with whom she shared fourteen hundred centimorgans, a measure of genetic overlap that typically denotes a half sibling. But this man was a stranger to her—and the site said that he had Sicilian ancestry.

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