Three months after his bone marrow transplant, Chris Long of Reno, Nev., learned that the DNA in his blood had changed. It had all been replaced by the DNA of his donor, a German man he had exchanged just a handful of messages with. It’s the goal of the procedure, after all: Weak blood is replaced by healthy blood, and with it, the DNA it contains. Even more surprising to Mr. Long and other colleagues at the crime lab, all of the DNA in his semen belonged to his donor. Mr. Long had become a chimera, the technical term for the rare person with two sets of DNA.

Source: New York Times December 07, 2019 09:56 UTC