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Biotech Science

Stem Cells Change Man's DNA 171

Posted by Zonk
from the oh-man-science-is-weird dept.
An anonymous reader writes "After receiving umbilical cord stem cells to replace bone marrow as treatment for non-Hodgkin's lymphoma, Greg Graves temporarily had three different sets of DNA. Eventually, one of the two sets of cells transplanted into his bone marrow took root, leaving him different DNA in his blood from the rest of his body: 'If you were to do a DNA test of my blood and one from my skin, they'd be different,' Graves said. 'It's a pretty wild thing.'"
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Stem Cells Change Man's DNA

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  • by debilo (612116) on Friday October 05, 2007 @05:30PM (#20873785)

    Perhaps this is the beginning of the end for the use of DNA as "incontrovertable" evidence in criminal cases?
    How so? The original DNA isn't gone or hidden. It still can be retrieved, you just need to take several different samples until you find a match.
  • by the_humeister (922869) on Friday October 05, 2007 @05:31PM (#20873807)
    We've been doing bone marrow stem-cell transplants for years on people with hematopoietic neoplasms. In fact, we've been doing solid organ transplants for about 40 years. Of course they will have different DNA! In fact, even a normal person has different sets of DNA right now. This is most evident in germ cells, which undergo meiosis, and antibody-producing hematopoietic cells, which change their DNA to be able to make different antibodies to different antigens. So I don't see why this is news.
  • This is nothing new. (Score:5, Informative)

    by wiggles (30088) on Friday October 05, 2007 @05:33PM (#20873827)
    The procedure is called an Allogenic Stem Cell Transplant. The procedure has been in use for well over a decade, and it replaced the old Bone Marrow Transplant techniques that used to be used for conditions such as leukemia, various cancers, lymphoma, and other immune system disorders.

    The only thing remarkable about this is the fact that the stem cells the man received were from cord blood instead of adult stem cells from a matched donor.

    Wikipedia has an excellent article on the subject: http://en.wikipedia.org/wiki/Stem_cell_transplantation [wikipedia.org]
    The applicable section to this article reads as such:
    "Umbilical cord blood is obtained when a mother donates her infant's umbilical cord and placenta after birth. Cord blood has a higher concentration of HSC (hematopoietic stem cells --ed.) than is normally found in adult blood. However, the small quantity of blood obtained from an umbilical cord (typically about 50 mL) makes it more suitable for transplantation into small children than into adults. Newer techniques using ex-vivo expansion of cord blood units or the use of two cord blood units from different donors are being explored to allow cord blood transplants to be used in adults."

    I spent six months in Seattle as a caregiver for a patient undergoing this procedure. The work they do at the Fred Hutchinson Cancer Research Center there is second to none.
  • by mendax (114116) on Friday October 05, 2007 @05:33PM (#20873829)
    You haven't been watching enough Law and Order! There was an episode that dealt with something like this. The man had a bone marrow transfusion. The DNA from his blood had one set of DNA and the rest of his body had another. Thus he could rape with impunity.
  • by zippthorne (748122) on Friday October 05, 2007 @05:34PM (#20873833) Journal
    Nothing would happen to his offspring. It's his bone marrow that has been replaced, not his testes.
  • by GuyverX (162940) on Friday October 05, 2007 @05:42PM (#20873949)
    It's ok. Calm down. Deep breath. This is actually not a terribly uncommon event when bone marrow transplants are used. The news seems to be that instead of transplanted bone marrow, he had stem cells from two different donors infused, and for a while both were found in his blood, but after a period of time only one of the lines seemed to survive. The "news" seems to be that this used stem cells which differentiated into new bone marrow for the patient.

    If it had been a "traditional" bone marrow transplant, he would STILL have had a second set of DNA found in his blood. This is becasue for this therapy to work, all of his native bone marrow is destroyed, completely. He will be physically incapable of making his own red, white, and platelet cells. The donor donated marrow is then given to him in the hopes that it will "take root" where his now-ablated marrow once was, and will take that function. It's just like a kidney or heart transplant, just much wetter.

    As for offspring due to the implanted cells, not gonna happen. The Gonads are very well protected from things like this, and just like with a transplanted solid organ, this only affects the somatic cells, not the germ cells created in his testes.

    So, just remember, think of the bone marrow and blood as another organ, and this is just another organ transplant. His biggest concern would be the effects of his chemo and radiation on his gonads, not the transplanted cells. Make sense?
  • by Ped Xing (28860) <.bruce. .at. .callenish.com.> on Friday October 05, 2007 @05:42PM (#20873953) Homepage
    No he is not, for several reasons.

    First, he is not the first to have two sets of DNA due to a bone marrow transplant (although he might be one of the first with 3 sets). Anyone who has had an allogeneic (as opposed to autologous) bone marrow transplant like his has that, as do any other transplant recipients.

    In fact, the differences between those DNA is both one of the best things and one of the worst things about alloBMTs to treat blood cancers. The new blood system sets itself up and sees the cancer cells as "foreign" and attacks them, what would be called "rejecting" them in a solid organ transplant. This is called "Graft Versus Leukemic Effect" in leukemia patients, for example. That's the good part. The bad part is that the new blood system looks at the rest of the body and sees it as foreign as well. "All this has to go" is the reaction, also called "Graft Versus Host Effect", or GVHD. That can kill you. Cord blood stem cells make this less likely to happen, because the cord blood cells are not quite sure what the other cells are supposed to look like yet.

    The second reason he is not the first man-made chimera is that he is not a chimera. A chimera is when the second set of DNA comes from another species. That has been done before (organ transplants from pigs, for example), but is not the case in this story.

    The real story here is that he had a stem cell transplant using cord blood from two different donors.
  • by UltraOne (79272) on Friday October 05, 2007 @06:17PM (#20874275) Homepage
    I am a pediatric blood and marrow transplant physician. After every successful bone marrow transplant (BMT), peripheral blood stem cell transplant (PBSCT), or umbilical cord blood transplant (UCBT) in which the donor is not the patient or an identical twin, the recipient becomes genetic chimera. The DNA in cells derived from the bone marrow stem cells is different from the DNA in the rest of the recipient's body.

    As others have pointed out, this isn't anything new. Significant clinical use of BMT dates back to the 1970's. PBSCT and UCBT came into widespread use in the late 1980's and early 1990's.

    My group performed a BMT on a patient with relapsed leukemia a few years ago. The patient unfortunately suffered liver and kidney damage as a result of the BMT. He had a liver transplanted from one donor and later a kidney from another donor. Fortunately, he recovered and has remained leukemia free. He is essentially back to being a normal kid, although he will need to take immunosuppressive mediations to prevent rejection indefinitely. That patient permanently has DNA from 4 different sources (bone marrow, liver, kidney, and his original genotype in all other parts of his body).
  • by Psykechan (255694) on Friday October 05, 2007 @06:20PM (#20874291)
    Yes, he would be a chimera at least for the time being. He has multiple DNA sources in his body and since both types of DNA can be obtained through blood, he could show up as two separate individuals if DNA testing were performed.

    The Lydia Fairchild story [go.com] is an interesting read. It's rare but it does happen.
  • by GooberToo (74388) on Friday October 05, 2007 @07:18PM (#20874823)
    Don't forget, while very rare, this can and does occur naturally.

    http://en.wikipedia.org/wiki/Chimera_(genetics) [wikipedia.org]
  • by squiggleslash (241428) on Friday October 05, 2007 @07:46PM (#20875079) Homepage Journal

    A chimera is when the second set of DNA comes from another species

    This is not true. Chimera is often used, outside of biology, to mean a creature made up of multiple species (a reference to Greek mythology) but in that instance you're not talking about biological chimerism, but some fiction where DNA is either not mentioned, or often is "merged" (cf Dark Angel.)

    However, when you're talking genetics, which is what we're talking about here, you're talking about a being that is the product of two zygotes (which is generally difficult, if not impossible, if they're of different species.)

    Chimeras using the biological definition are, if not common, certainly abundant, and there have been court cases involving people whose DNA tests didn't work because they were chimeras. Chimeras are particularly common if the person was conceived via IVF.

  • by WhatAmIDoingHere (742870) * <sexwithanimals@gmail.com> on Friday October 05, 2007 @07:55PM (#20875169) Homepage
    The magic words when you have to go to court are as follows:

    Reasonable Doubt.
  • Re:Change or add? (Score:3, Informative)

    by Sique (173459) on Saturday October 06, 2007 @05:23AM (#20877747) Homepage
    Because the new stemcells replaced the old in the bone marrow. So his blood DNA slowly changed from his own to that of the new stem cells. First there were only blood cells from his DNA, and very few of the new one. Later one the blood cells with his own DNA got replaced by those produced from the new stem cells.

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