People who receive a bone marrow transplant may get more than they bargained for, according to a new case study. Criminal forensic investigators conducted the study on bone marrow recipient Chris Long of Reno, Nev., to see if such transplants could lead to erroneous DNA testing in criminal investigations, The New York Times reported.
They found that three months after the transplant to treat Long’s leukemia, his donor’s DNA had replaced all of his own DNA in his blood. Four years later, swabs of his lips and cheeks contained both his and his donor’s DNA. Even more astonishing, 100 percent of the DNA in his semen belonged to his donor.
Andrew Rezvani, the medical director of the inpatient Blood & Marrow Transplant Unit at the Stanford University Medical Center, said donor DNA should not affect a person’s traits. “Their brain and their personality should remain the same,” he told the Times. But it could become complicated if a patient’s donor becomes involved in a crime.
Every year, tens of thousands of people in the United States receive bone marrow transplants. In 2004, investigators in Alaska found that the DNA of a potential suspect matched samples gathered at the scene of an assault. But the suspect, incarcerated at the time, could not have committed the crime. Eventually, investigators learned that the man’s brother had donated bone marrow to him. They convicted the brother.
In another case, police investigators doubted a sexual assault victim because she claimed only one person attacked her, but analysis showed DNA from two people. Later, they learned that the second set of DNA belonged to her bone marrow donor.
And in 2008 Yongbin Eom, a visiting research scholar at the University of North Texas Center for Human Identification, was shocked to discover that blood tests found female DNA from a traffic accident victim who appeared to be male. DNA testing from a kidney confirmed the individual was male, but samples from the spleen and lung contained both male and female DNA. It turned out the victim had received a bone marrow transplant from his daughter. —J.B.