The DNA in his semen was completely replaced with another man's DNA

Originally published at:

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Woah, so are they saying that any kids the guy has will effectively be his donor’s?


Ugh, all of the reporting on this has been so misleading. As it says buried in the article you linked to, the man had a vasectomy. So his semen contains no sperm and he cannot have kids. If it did contain sperm it would be his, not the donors. Bone marrow cells create blood cells and could not create sperm. His semen contains traces of his blood cells so it tests positive for the bone marrow donor DNA. Please correct your original article.


No, see my other comment.


That’s how they make magnets.


Thanks for clarifying. I should really have clicked through!


What a bizarre story. It quotes experts saying that it’s impossible for this guy to pass on the donor’s genes, but if the DNA in his sperm is entirely the donor’s then obviously that is exactly what would happen.

It seems remarkable that medical science would never have studied this, and forensic techs would have found such an extreme result.

Very strange story, and as @FrancesTheMute points out possibly misleading or outright wrong.

For one thing the conditioning involved when receiving a bone marrow transplant leaves the recipient infertile (lots of radiation is required!).

So whether or not he’d had a vasectomy I don’t think what’s described makes any sense.


I do not think this would be possible. A bone marrow transplant specifically replaces bone marrow which has nothing whatsoever to do with germ cell lines. This is one of the worries with gene therapy, whether it can change germ cell lines, but I do not think bone marrow can do that. There are blood cells in semen and those, being a product of bone marrow, will be the donor’s DNA. Any sperm (vasectomy notwithstanding, he still makes sperm, it just can’t go anywhere) should still be his own genotype.

Now, let me qualify this by saying that I am logicking this, not based on research or facts or stuff like that!


I approve. Let us stick with Logic. Facts can be so misleading. :smiley:


Oh - if he had a vasectomy that does clear things up a bit, since it means there are no sperm in his semen.

Still, they are claiming there is donor DNA in cheek swabs and stuff, and the article makes it sound like we’re talking about mosaicism. I assume the scientific consensus is that that doesn’t happen - that all these surprising results simply reflect the presence of donor white blood cells in lots of different samples - but it’s just all very odd how they’re talking about “research” done by lab techs and not even really mentioning what science has to say on the topic.


OK, so it appears this is a rare but known occurrence, at least in somatic cells. No mention of germ cells, though. Humans are weird.


Wait, is that true?

Not about the magnets, about the witches.

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Oh thanks for the details, because I am like, how the hell could this happen?

I guess we forget semen has other cells in it besides just sperm.

Boing Boing doesn’t correct inaccuracies except when they’re seriously embarrassing for Boing Boing. They certainly won’t correct click-bait - which is what the headline is there for.

They carefully said “semen” in the title, which was factually accurate, and totally misleading. They know that the majority of readers will see “semen” and think “sperm” - but this guy’s semen had no sperm in it, just white blood cells that had the donor’s DNA. Typical click-bait writing.


I wonder what kind of IRB the Washoe County sheriff’s office has?

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And now he likes Italian food.


This has been the common way of (mis)representing the story, though. I’ve seen this get reported by multiple outlets and no one is making it clear up front that we’re not talking about sperm here. (It doesn’t help that they quote a guy giving incorrect information in the original story.)

Yeah, I’m not sure why this is remotely surprising - everyone knew that bone marrow donor DNA via the blood cells gets just about everywhere. His DNA was still in his cheek swab, it just also had the marrow donor DNA, so even that shouldn’t have been too surprising; it’s just weird that at one point a criminalist claims the guy’s DNA “was no longer present at all,” when the information given directly contradicts him.

Ultimately this story doesn’t give me confidence in police lab techs.


It’s the gift that keeps on giving. :wink:

Archie Bunker and the transfusion.