Nevada resident Chris Long received a piece of shocking news recently. Four years ago Chris was diagnosed with leukemia, for which he had received bone marrow transplant. Chris was recently informed that his body now shares his donor’s DNA strain!
The presence of the donor’s DNA is not only there in Chris’ blood. It can also be found in his cheeks and lips. Surprisingly enough, the DNA found in Chris’ semen is exclusively that of the donor’s. This has raised some pertinent questions regarding heredity as well as criminal forensics. This “genetic chimera” has brought forth some revolutionary changes in our knowledge and understanding of the human DNA, criminal forensics as well as donor-recipient relations.
5000 Miles Apart
Chris was suffering from myelodysplastic syndromes and acute myeloid leukemia because of which his body was incapable of producing new blood. Upon diagnosis, he sought a compatible donor through a matching website.
The transplant Chris received belonged to a much younger man from Germany. After hearing about the transplant, Renee Romero, a colleague of Chris Long, was curious. She wanted to take a few swabs to run DNA tests. She was aware that a successful bone marrow transplant results in the DNA of the donor taking over the recipient’s body. Romero was, however, unaware of the full extent of it.
Only after a couple of months post the transplant, Chris’ body started to change radically. The DNA present in Chris’ blood was that of the donor’s–a German man whom he had never even met in person.
While the donor material taking over the recipient body is a reassuring proof of a successful transplant, the donor-recipient DNA tussle was an under-researched area. The Sheriff’s Department of Washoe County, as a result, decided to research further and shed some light on it.
The Uncertainties of DNA Testing
After almost a year, when Chris submitted his DNA for a new round of testing, it led to a shocking revelation. The genetic material of his lips, cheeks, and tongue swabs was a mixture of two sets of DNA. What startled Chris, even more, was 100% of his semen DNA was that of his donor’s. The only unaffected part was the hair belonging to his chest and head.
In a field where DNA testing can make and break a criminal case, such startling revelations are shaking the very foundations. The certainty brought forth by the testing in forensics is now being challenged by this discovery.
This issue of “genetic chimera” was explored further by Brittney Chilton, Chris’ colleague. She discovered a 2005 case, where the victim claimed to be assaulted by a single individual. Yet, the Alaska State Scientific Crime Detection Laboratory revealed two distinct sets. Upon further exploration, it was discovered that the second set was that of the donor’s.
The once fail-proof DNA testing has now become questionable due to donor-recipient genetic chimerism. It has also opened up newer avenues of research in genetics.
Image Credit: Supharit Sriarunchai