By Jonathan Frazier

A man who received a bone marrow transplant took a DNA test four months later that said he wasn’t who he claimed to be.

While training for a half-mile marathon, Chris Long from Reno, Nevada was diagnosed with Acute Myeloid Leukemia / Myelodysplastic Syndromes (AML/MDS) . This is the most common form of Leukemia in adults today. Along with six rounds of chemotherapy, Long was treated with a bone marrow transplant from a healthy, young man in Europe. The white blood cells were introduced directly into Long’s bloodstream.

After months of digestive issues, mouth sores, and weight loss, New York Times says Chris Long “had been encouraged to test his blood by a colleague at the Sheriff’s Office, where he worked”. The colleague also motioned for Long to have a study done of the anomalies he was experiencing. These both lead to one conclusion— Chimerism.

Chimerism, by definition, a single being that houses the genetic structure of two or more beings. According to the study published under the Forensic Science Division of the Washoe County Sheriff’s Office, after just four months following the transfusion, Long’s blood results came back 100% donor’s blood. However, other DNA swabs, such as mouth the mouth swabs conducted in 2019, came back no more than 35% donor DNA.

The study goes on to explain the significance of these events to criminal forensics:

Previously thought of chimeras as an individual with tissues that had distinct genomes. However, many of the results we observed were mixtures. These would have been reported as a mixture of at “least two individuals” which could be misleading for a case.

Washoe County Sheriff’s Office Forensic Science Division

The implications of multiple DNA counts in one person has heavy implications for criminal investigations. New York Times presents, for exapmle, that if a sexual assault victim says there had been one attacker but the DNA analysis shows two, this may cause skepticism among investigators.

WCSO stresses the importance of investigators keeping an open mind to situations as such despite its rarity. They, in fact, expect to see more individuals in there “multi-allelic offender category”.

PHOTO CREDIT Chris Long, WCSO