Not human, lion-fronted and snake behind, a goat in the middle
October 27, 2015 5:09 AM Subscribe
When a Washington couple failed a paternity test, they thought the fertility clinic had used the wrong sperm. But the clinic was pretty sure it hadn't. A more detailed fertility test showed that the father wasn't the father -- his never-born twin brother was.
Karen Keegan looked to see if her sons could donate kidneys, and found that although her three sons were brothers, only two of them were her sons. This story proved helpful for Lydia Fairchild, who was being accused of welfare fraud after her two children showed no genetic link to her. She was at the time pregnant, and a witness was present at the birth of a third child which showed no genetic link to her.
Chimerism, though becoming increasingly common with fertility treatments, is universal in other primates.
Karen Keegan looked to see if her sons could donate kidneys, and found that although her three sons were brothers, only two of them were her sons. This story proved helpful for Lydia Fairchild, who was being accused of welfare fraud after her two children showed no genetic link to her. She was at the time pregnant, and a witness was present at the birth of a third child which showed no genetic link to her.
Chimerism, though becoming increasingly common with fertility treatments, is universal in other primates.
Absolutely wild.
posted by ThePinkSuperhero at 5:19 AM on October 27, 2015
posted by ThePinkSuperhero at 5:19 AM on October 27, 2015
Possibly more than two bioparents. Possibly more than one soul?
posted by XMLicious at 5:25 AM on October 27, 2015
posted by XMLicious at 5:25 AM on October 27, 2015
It is an intriguing thought on several levels to think that some of us may have immediate ancestors who were never born.
posted by ricochet biscuit at 5:31 AM on October 27, 2015 [12 favorites]
posted by ricochet biscuit at 5:31 AM on October 27, 2015 [12 favorites]
I have to admit I kinda wish I was a chimera. It sounds pretty badass.
posted by ian1977 at 5:34 AM on October 27, 2015
posted by ian1977 at 5:34 AM on October 27, 2015
Widespread DNA testing has lead to all sorts of interesting things. There are a number of papers published over the years on humans and other animals using DNA to measure how often the presumed father is not the actual/genetic father in various populations. I wonder if those results take chimerism into account or if the results need to be reassessed in light of new knowledge.
posted by TedW at 5:37 AM on October 27, 2015 [3 favorites]
posted by TedW at 5:37 AM on October 27, 2015 [3 favorites]
This is frankly mindblowing. Truly. I hope the people who were affected by this got (or get) things sorted out.
Wonder what the creationists make of all this.
posted by marienbad at 5:37 AM on October 27, 2015 [2 favorites]
Wonder what the creationists make of all this.
posted by marienbad at 5:37 AM on October 27, 2015 [2 favorites]
I have to admit I kinda wish I was a chimera. It sounds pretty badass.
How do you know you aren't?
posted by TedW at 5:39 AM on October 27, 2015 [6 favorites]
How do you know you aren't?
posted by TedW at 5:39 AM on October 27, 2015 [6 favorites]
I kinda thought the "never-born twin" framing was weird. How do you tell which of the twins was born and which wasn't? Is it a 51%/49% thing?
When the chimaeric person gets to heaven will all of the body parts with the "wrong" genome be missing? Or replaced with tissue of the "right" genome?
posted by XMLicious at 5:42 AM on October 27, 2015
When the chimaeric person gets to heaven will all of the body parts with the "wrong" genome be missing? Or replaced with tissue of the "right" genome?
posted by XMLicious at 5:42 AM on October 27, 2015
During pregnancy, cells from the placenta of the fetus often get into the mother's bloodstream, establish themselves somewhere in the mother's body, and stay there long after the pregnancy. This is called fetomaternal microchimerism. In "Male Microchimerism in the Human Female Brain", Chan and colleagues find that 63% of autopsied women in their sample had signs of Y chromosome DNA in their brains. They concluded this was the result of fetomaternal microchimerism.
posted by grouse at 5:45 AM on October 27, 2015 [5 favorites]
posted by grouse at 5:45 AM on October 27, 2015 [5 favorites]
Wonder what the creationists make of all this.
Just God and/or Satan fucking with the nonbelievers again.
posted by TedW at 5:45 AM on October 27, 2015 [2 favorites]
Just God and/or Satan fucking with the nonbelievers again.
posted by TedW at 5:45 AM on October 27, 2015 [2 favorites]
Chimeric monkeys are cuter than chimeric humans, though.
posted by ChuraChura at 5:54 AM on October 27, 2015
posted by ChuraChura at 5:54 AM on October 27, 2015
How do you tell which of the twins was born and which wasn't?
Q. Well, I never heard anything like this. Somebody was dead. Somebody was buried. Now, where was the mystery?
A. Ah, that's just it! That's it exactly. You see we were twins,--defunct and I,--and we got mixed in the bath-tub when we were only two weeks old, and one of us was drowned. But we didn't know which. Some think it was Bill, some think it was me.
Q. Well, that is remarkable. What do you think?
A. Goodness knows! I would give whole worlds to know. This solemn, this awful mystery has cast a gloom over my whole life. But I will tell you a secret now, which I never have revealed to any creature before. One of us had a peculiar mark, a large mole on the back of the left hand,--that was me. That child was the one that was drowned.
posted by DaDaDaDave at 6:06 AM on October 27, 2015 [14 favorites]
Q. Well, I never heard anything like this. Somebody was dead. Somebody was buried. Now, where was the mystery?
A. Ah, that's just it! That's it exactly. You see we were twins,--defunct and I,--and we got mixed in the bath-tub when we were only two weeks old, and one of us was drowned. But we didn't know which. Some think it was Bill, some think it was me.
Q. Well, that is remarkable. What do you think?
A. Goodness knows! I would give whole worlds to know. This solemn, this awful mystery has cast a gloom over my whole life. But I will tell you a secret now, which I never have revealed to any creature before. One of us had a peculiar mark, a large mole on the back of the left hand,--that was me. That child was the one that was drowned.
posted by DaDaDaDave at 6:06 AM on October 27, 2015 [14 favorites]
This is one of my many, many arguments as to why a fertilised egg/zygote/stem cell/embryo is not a person. There can be all sorts of arguments about what makes personhood, but that isn't the line.
It's the recipe for a person, the architectural drawing for a person. The difference between a house with people inside, and the draft plans.
If you put two or more zygotes really, really close together, they'll just start creating a single being. Click, whirr, divide up into cells, and start specialising into what cells are required. If you put one into a toe, they'd become toe cells (nails, skin muscle, whatever). It would still be alive.
[An immune system response may identify some as 'foreign' and attempt to destroy them, but it's still possible]
Someone with chimerism isn't two people, they're one person. And identical twins are not 'one person' but two. It's kind of similar really, an early stage embryo gets a little too separated early in the cell divisions, and forms two (or more - most recorded is five) fetuses, with the same dna.
When non-identical fraternal twin zygotes/embryos are too close together, or one is absorbed by the other, then you get one person with two different genetic lines.
They don't have to be the same sex either, you can get intersex chimeras.
Genetic chimerism is almost definitely more common than people think, just because there would be no reason for it to be tested for, so why would it come up?
I think putting 'no genetic link' to her in the post above, confuses the issue unnecessarily.
There was a genetic link as the DNA lines have the same parents. The gene line they tested would have been the genetic 'sibling' or fraternal twin (same mother and father) of the other line.
But even the whole uncle thing implies that the child wasn't parented by the human being who is the father.
The father is still the father, the mother is still the mother, they just tested the wrong DNA lines initially (often one line is more predominant in the blood, etc, it's usually mosaic patchwork throughout the body), and didn't realise there were at least two genetic lines present.
posted by Elysum at 6:37 AM on October 27, 2015 [31 favorites]
It's the recipe for a person, the architectural drawing for a person. The difference between a house with people inside, and the draft plans.
If you put two or more zygotes really, really close together, they'll just start creating a single being. Click, whirr, divide up into cells, and start specialising into what cells are required. If you put one into a toe, they'd become toe cells (nails, skin muscle, whatever). It would still be alive.
[An immune system response may identify some as 'foreign' and attempt to destroy them, but it's still possible]
Someone with chimerism isn't two people, they're one person. And identical twins are not 'one person' but two. It's kind of similar really, an early stage embryo gets a little too separated early in the cell divisions, and forms two (or more - most recorded is five) fetuses, with the same dna.
When non-identical fraternal twin zygotes/embryos are too close together, or one is absorbed by the other, then you get one person with two different genetic lines.
They don't have to be the same sex either, you can get intersex chimeras.
Genetic chimerism is almost definitely more common than people think, just because there would be no reason for it to be tested for, so why would it come up?
I think putting 'no genetic link' to her in the post above, confuses the issue unnecessarily.
There was a genetic link as the DNA lines have the same parents. The gene line they tested would have been the genetic 'sibling' or fraternal twin (same mother and father) of the other line.
But even the whole uncle thing implies that the child wasn't parented by the human being who is the father.
The father is still the father, the mother is still the mother, they just tested the wrong DNA lines initially (often one line is more predominant in the blood, etc, it's usually mosaic patchwork throughout the body), and didn't realise there were at least two genetic lines present.
posted by Elysum at 6:37 AM on October 27, 2015 [31 favorites]
Somewhere people who worked in the original CSI series are regretting just learning about this because it would be super easy to pull off as a story in Vegas and somewhere else currently working writers are trying to figure out how to make this a cyber crime for the current incarnation.
posted by MCMikeNamara at 6:41 AM on October 27, 2015
posted by MCMikeNamara at 6:41 AM on October 27, 2015
I think this is interesting and cool, but also really fucked up. This seems like something that could have an enormous impact on public health policy, and I was surprised that it wasn't addressed in the article. Not to mention that every single paternity test ever done is now suspect. How many children have lost the right to child support from their real fathers because the test came back negative?
posted by lollymccatburglar at 6:42 AM on October 27, 2015 [3 favorites]
posted by lollymccatburglar at 6:42 AM on October 27, 2015 [3 favorites]
How do you know you aren't?
My secret evil twin Hector whispers in my ear that no way we are a chimera. He's a party pooper.
posted by ian1977 at 6:44 AM on October 27, 2015 [1 favorite]
My secret evil twin Hector whispers in my ear that no way we are a chimera. He's a party pooper.
posted by ian1977 at 6:44 AM on October 27, 2015 [1 favorite]
And while I'm at it, let's toss in Pitch Perfect to cover all the bases.
posted by rum-soaked space hobo at 6:56 AM on October 27, 2015
posted by rum-soaked space hobo at 6:56 AM on October 27, 2015
How many children have lost the right to child support from their real fathers because the test came back negative?
Probably not many, unless this is a lot more prevalent than indicated. In this case, the child turned up "not his" because the father's sperm cells where where the chimerism was. If it had been his big toe or his liver that had those cells, it would never have been discovered.
posted by emjaybee at 6:59 AM on October 27, 2015 [2 favorites]
Probably not many, unless this is a lot more prevalent than indicated. In this case, the child turned up "not his" because the father's sperm cells where where the chimerism was. If it had been his big toe or his liver that had those cells, it would never have been discovered.
posted by emjaybee at 6:59 AM on October 27, 2015 [2 favorites]
In this case, the child turned up "not his" because the father's sperm cells where where the chimerism was.
More specifically, the father's sperm cells and cheek lining cells were from different DNA lines and they don't test for that many markers when they do paternity testing.
I would assume it's more prevalent than we think because there hasn't been easy DNA testing for long, and suspect that those statistics like 24% of kids/fraternal twins/whatever have different biological fathers than they think are actually affected by chimerism.
posted by jeather at 7:11 AM on October 27, 2015
More specifically, the father's sperm cells and cheek lining cells were from different DNA lines and they don't test for that many markers when they do paternity testing.
I would assume it's more prevalent than we think because there hasn't been easy DNA testing for long, and suspect that those statistics like 24% of kids/fraternal twins/whatever have different biological fathers than they think are actually affected by chimerism.
posted by jeather at 7:11 AM on October 27, 2015
I have a family member with two different color eyes and I remember being told they were a chimera as a child -- at least 15-20 years ago now? Possibly longer? It is definitely something that I ponder from time to time. As far as I know it's never really affected their life in any way.
Related question: Is everyone with different-colored eyes a chimera?
And while I'm at it, let's toss in Pitch Perfect to cover all the bases.
Also Dwight Schrute. And Orphan Black (not saying who as I guess it's a spoiler for part of last season).
posted by pie ninja at 7:23 AM on October 27, 2015 [1 favorite]
Related question: Is everyone with different-colored eyes a chimera?
And while I'm at it, let's toss in Pitch Perfect to cover all the bases.
Also Dwight Schrute. And Orphan Black (not saying who as I guess it's a spoiler for part of last season).
posted by pie ninja at 7:23 AM on October 27, 2015 [1 favorite]
I liked how towards the end of the article, they casually slip in that the dad was striped. Just FYI.
posted by artychoke at 7:26 AM on October 27, 2015 [8 favorites]
posted by artychoke at 7:26 AM on October 27, 2015 [8 favorites]
Right? I am dying to see a picture of a striped guy. What color are the stripes? Are they all over his body? Is he mottled or striped like a tiger? What about his hair?
posted by jfwlucy at 7:41 AM on October 27, 2015 [5 favorites]
posted by jfwlucy at 7:41 AM on October 27, 2015 [5 favorites]
If only one of the two genomes is represented in the sperm or eggs, it raises an issue of 'cheating', where the other genome does all this work but has no prospect of getting passed on -- not to mention the hash it makes of Darwinian selection (for that generation).
posted by jamjam at 7:46 AM on October 27, 2015 [4 favorites]
posted by jamjam at 7:46 AM on October 27, 2015 [4 favorites]
I too am disappointed that I was probably not a fetal cannibal.
posted by poffin boffin at 7:56 AM on October 27, 2015 [1 favorite]
posted by poffin boffin at 7:56 AM on October 27, 2015 [1 favorite]
MCMikeNamara Somewhere people who worked in the original CSI series are regretting just learning about this because it would be super easy to pull off as a story in Vegas
Already done
That episode was actually how I learned about chimerism in the first place...TV is educational! Everyone watch TV!
posted by sprezzy at 8:19 AM on October 27, 2015 [7 favorites]
Already done
That episode was actually how I learned about chimerism in the first place...TV is educational! Everyone watch TV!
posted by sprezzy at 8:19 AM on October 27, 2015 [7 favorites]
I know it would violate all manner of privacy etiquette, but I would love to see a picture of the stripes. I assume it has to do with the way the cells with different DNA are dispersed throughout the body.
posted by Soliloquy at 8:20 AM on October 27, 2015
posted by Soliloquy at 8:20 AM on October 27, 2015
There are some pictures of chimera striping online
posted by sprezzy at 8:28 AM on October 27, 2015 [2 favorites]
posted by sprezzy at 8:28 AM on October 27, 2015 [2 favorites]
I have nothing useful to add, but I feel I should say something.
posted by chimaera at 8:31 AM on October 27, 2015 [13 favorites]
posted by chimaera at 8:31 AM on October 27, 2015 [13 favorites]
Well, you don't, but what about you2?
posted by jamjam at 9:10 AM on October 27, 2015 [5 favorites]
posted by jamjam at 9:10 AM on October 27, 2015 [5 favorites]
Related question: Is everyone with different-colored eyes a chimera?
No, but a few are.
It's called Heterochromia iridum, if you want to look up all the different reasons.
Aquired, is from infection or disease (e.g. David Bowie doesn't actually have two different coloured eyes, he has one iris which is permanently enlarged...).
There are hereditary/genetic conditions, like Waardenburg syndrome (frequently has a white patch of hair, also). Basically various conditions cause less melanin in parts of the body, so think of it as kind of like vitiligo but affecting one eye - that's why one 'blue' eye is pretty common, because it's just less melanin.
But yeah, chimeraism and mosaicism are the cause for SOME heterochromia.
Mosaicism is similar to chimerism - but instead, where one of the cells in a single embryo has a mutation or division error really early on, so you get (like chimeraism), two genetic lines occurring in the body, but with mosaicism, they are from the same initial fertilized egg, so other than the mutation (which could be really severe, or involve extra chromosomes, etc etc), they are genetically identical.
I've heard of a few examples where it turns out someone who is surviving/beating the odds on a really terrible genetic conditions, it's because they have have SOME cells in their body which don't have that genetic condition.
We basically all have some mosaic cells, just because of, essentially, copy errors. When you get a cancer, that's basically a copy error.
posted by Elysum at 9:19 AM on October 27, 2015 [4 favorites]
No, but a few are.
It's called Heterochromia iridum, if you want to look up all the different reasons.
Aquired, is from infection or disease (e.g. David Bowie doesn't actually have two different coloured eyes, he has one iris which is permanently enlarged...).
There are hereditary/genetic conditions, like Waardenburg syndrome (frequently has a white patch of hair, also). Basically various conditions cause less melanin in parts of the body, so think of it as kind of like vitiligo but affecting one eye - that's why one 'blue' eye is pretty common, because it's just less melanin.
But yeah, chimeraism and mosaicism are the cause for SOME heterochromia.
Mosaicism is similar to chimerism - but instead, where one of the cells in a single embryo has a mutation or division error really early on, so you get (like chimeraism), two genetic lines occurring in the body, but with mosaicism, they are from the same initial fertilized egg, so other than the mutation (which could be really severe, or involve extra chromosomes, etc etc), they are genetically identical.
I've heard of a few examples where it turns out someone who is surviving/beating the odds on a really terrible genetic conditions, it's because they have have SOME cells in their body which don't have that genetic condition.
We basically all have some mosaic cells, just because of, essentially, copy errors. When you get a cancer, that's basically a copy error.
posted by Elysum at 9:19 AM on October 27, 2015 [4 favorites]
This is fascinating, but Chimera is entirely the wrong mythological beast to name the syndrome after. In fact, what we have here is the Great Roe: a beast (according to Woody Allen) with the head of a lion and the body of a lion, but it's not the same lion.
posted by The Bellman at 10:47 AM on October 27, 2015 [6 favorites]
posted by The Bellman at 10:47 AM on October 27, 2015 [6 favorites]
Re: heterochromia: Thank you -- that's fascinating.
posted by pie ninja at 12:04 PM on October 27, 2015
posted by pie ninja at 12:04 PM on October 27, 2015
A friend of mine is about to get a BMT and will effectively become a chimera, though I doubt they will develop the fancy stripes.
posted by grumpybear69 at 1:02 PM on October 27, 2015
posted by grumpybear69 at 1:02 PM on October 27, 2015
Somewhere people who worked in the original CSI series are regretting just learning about this because it would be super easy to pull off as a story in Vegas and somewhere else currently working writers are trying to figure out how to make this a cyber crime for the current incarnation.
Actually, I'm pretty sure this was a CSI plotline many years back. They got a DNA match for a rape or murder, and it said that the perp was the match's brother, but they couldn't find a brother, and then they came up with the chimera thing. They even did the ultraviolet show the skin striping thing.
posted by tavella at 1:04 PM on October 27, 2015
Actually, I'm pretty sure this was a CSI plotline many years back. They got a DNA match for a rape or murder, and it said that the perp was the match's brother, but they couldn't find a brother, and then they came up with the chimera thing. They even did the ultraviolet show the skin striping thing.
posted by tavella at 1:04 PM on October 27, 2015
I have to admit I kinda wish I was a chimera. It sounds pretty badass.
I'm of two minds on the topic, personally.
posted by Pater Aletheias at 3:26 PM on October 27, 2015 [3 favorites]
I'm of two minds on the topic, personally.
posted by Pater Aletheias at 3:26 PM on October 27, 2015 [3 favorites]
I dunno. I'd still rather be fused with a machine, as long as it isn't something boring like a pacemaker or insulin pump.
posted by Halloween Jack at 3:48 PM on October 27, 2015
posted by Halloween Jack at 3:48 PM on October 27, 2015
Also two episodes of Without A Trace, which is what I first thought of. Tony Goldwyn as the identical twins, one good, one bad.
posted by gadge emeritus at 5:11 PM on October 27, 2015
posted by gadge emeritus at 5:11 PM on October 27, 2015
I too am disappointed that I was probably not a fetal cannibal.
It's never too late to start!
posted by um at 8:01 PM on October 27, 2015
It's never too late to start!
posted by um at 8:01 PM on October 27, 2015
Is this the plot of season Six of The Venture Brothers?
posted by Abehammerb Lincoln at 8:39 PM on October 27, 2015
posted by Abehammerb Lincoln at 8:39 PM on October 27, 2015
I imagine these parents will have authority problems with this kid...
"You can't tell me what to do, you're not my real dad!!"
posted by switcheroo at 5:00 PM on October 28, 2015
"You can't tell me what to do, you're not my real dad!!"
posted by switcheroo at 5:00 PM on October 28, 2015
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posted by roomthreeseventeen at 5:15 AM on October 27, 2015