I was watching one of the many forensic police shows (it may have been “CSI: Assboink, Idaho”) and in it there was man who had received a bone marrow transplant, and because blood comes from the bone marrow the DNA of his blood was that of the donor, and did not match his “original” DNA (like, of his sperm).
This sounded plausible, is this actually the case with recipients of bone marrow transplants?
In general, do those who receive a bone marrow transplant have no original marrow left at all? Or is it sometimes or always the case they have a mixture of both original and new marrow, and perhaps have blood of both DNA sets?
I know that bone marrow can definitely cause someone to change their blood type (say from and A to an O), because IIRC bone marrow is matched to HLA groups rather than simply blood type.
Our Molecular Sequencing lab has a test specifically designed to test how well bone marrow transplants are “taking” by periodicially testing the genetic profile of the patient’s bone marrow samples. If a patient goes from 90% recipient/10% donor to 50%/50% to 10%/90%, it’s a good sign that the donated bone marrow is growing well.
If I understand correctly, some procedures require the marrow to be completely destroyed. If you have leukemia, they kill off the bone marrow because that’s where some of the cancerous cells come from. My guess, then, is that when that’s the case, the DNA would only reflect the donor.
That’s assuming both types of marrow are producing blood cells at the same rate, which may or may not be true, especially if the original marrow is cancerous, and thus dividing like mad.