Quote Sasha88: MYSTERY SOLVED!!!
It WAS bone marrow!!! I found info online that bone marrow transplants involved destroying the patient's own bone marrow. In such cases their blood will contain the DNA profile of the donor alone.
I'm retired from the Criminal Justice System. Tell me where you found this amazing information. The things people will believe, gee whizzz.
That's right. The reason for a bone marrow transplant is that the marrow has been destroyed, either by a disease or, in what we see most often, by massive doses of chemo and/or radiation used to destroy a disease like cancer. The treatment destroys the "good" bone marrow along with the "bad" disease, and so the marrow needs replacing. When it is, the blood which it eventually creates takes on the genetic profile of the donor, although the body tissues can reflect those of the recipient. That's why the donor and recipient have to be compatible for the transplant to work (ie, not to be rejected by the donor). Since blood and/or bone marrow (in bones and/or marrow of burned or long-buried or embalmed bodies) is most commonly sampled to match bodies, it's possible that a bone marrow donor could be matched to a recipient that way.
I know this because I had a transplant myself and have been counseling others in the same boat for years.