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When did you first learn of human chimerism? This story is from 2006, about a dispute in 2002. Social workers aren't the most scientifically-literate, and burea
by gojomo 12y ago
When did you first learn of human chimerism? This story is from 2006, about a dispute in 2002. Social workers aren't the most scientifically-literate, and bureaucracies are often under the spell of folklore-beliefs in the certainty of genetic science, picked up from TV or state prosecutors. (Even medical 'professionals' aren't always up-to-date on topics that were considered only vanishingly-rare curiosities, when they were in med school decades ago.)
Awareness of chimerism has risen a lot in the last decade, and if you learned about it yourself in the last 10 years, it might have been due to followup coverage from this and similar cases.
And while this 2006 article describes it as a 'rare' condition ("only 30 documented cases worldwide"), in fact the more scientists look the more they find it. There's since been evidence that on a small scale, cells pass from mother-to-child and child-to-mother in the womb, and these cells are still present in blood or brain decades later... meaning almost everyone might
be a chimera.
http://www.nytimes.com/2013/09/17/science/dna-double-take.html?pagewanted=all http://www.nytimes.com/2013/09/17/science/dna-double-take.ht...
- rjsw 12y agoThere was a CSI episode from 2004 that had a human chimera as the villain.
- jkldotio 12y agoThe USA has 319 million people, that means every federal agency is going to have to deal with hundreds of "one in a million" cases, so handling something "rare" badly is still worthy of criticism. Chimerism in humans was reported on in medical journals, and as an issue for tests, since at least the 1950s and appears in the titles of all sorts of academic papers from the fields of biology and medicine from there to now. I would have thought that if the father is saying she's the mother, she's saying she's the mother, she has the birth certificates saying that she's the mother, witnesses to the births like her parents and there is no person missing those children or claiming to be the real mother it would be reasonable to consider the possibility it is an edge case even if you still thought fraud was more likely.
- gojomo 12y agoWasn't a federal agency; instead a subdivision that has 2% of the US population. So, it's possible in a hundred years, most such bureaucracies won't see a single such case. Caseworkers don't Google extreme scenarios regarding obscure words ("chimerism") that they've probably never heard of before. Apparently, neither the mother nor her own obstetrician nor her lawyer came up with this theory, either, for quite a while, so who's fault is that? (The people with the most at stake couldn't find the magic research promptly, either.) It wasn't until after the 2002 paper about the Keegan case, and then other media coverage of this Fairchild case, and then followup stories/dramas and more recent research, that people outside of research had any idea anything like this could happen. No, low-level state caseworkers are not going to come up with the idea themselves. And the fact they kept running tests, including monitoring a live-birth-and-immediate-DNA-test, and deferring final judgement, indicates that the system was entertaining the possibility that this was an edge case. There's some serious hindsight bias in the know-it-all criticisms here.
- dekhn 12y agoI first learned about chimerism in the early 2000s, but it was a huge shock to me (it has some very deep implications beyond the scope of this article), and I was a biologist at the time. Long ago I was pretty skeptical of the absurdly high confidence levels in forensic DNA testing because they made a number of very basic assumptions, which chimerism (among other things) show to be wrong, at a rate within the population which is higher than the reported confidence rate.