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General => Ancestral Family Tree DNA Testing => Topic started by: BushInn1746 on Wednesday 19 September 18 16:07 BST (UK)
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Genetic Chimerism
After DNA testing in Benefit and other challanges in the United States, 30 cases in the US have uncovered Chimerism.
It seemed to begin when Lydia Fairchild tried to claim her child benefit for her three children and she was refused. In the US when claiming benefit for children it was necessary for the Claimant and Children to have a DNA Test.
A second DNA test of Lydia and her children also confirmed her three children were not her children, according to DNA testing.
The Case was Appealed.
It has been discovered that when the fetus was in the womb, the development process had begun with twins early on, but the twin's DNA had been absorbed into the other surviving fetus.
The Mother having a DNA test, has the different DNA of her fetus twin (the twin which never developed).
Her children she gave birth to, have other DNA!!
Other cases have been appealed and also made the subject of scientific analysis and investigation and 30 cases in the US have been found of Chimera.
Mark
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I'd like to know more about "... the twins' DNA had been absorbed into the other surviving foetus."
Martin
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Hello Martin
The case has been mentioned on BBC 2 presented by Chris Packham, the 'World's Weirdest Events'.
Mark
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Martin, Hope this was it, my Wife thinks it was Episode 6
https://www.bbc.co.uk/programmes/b069b2qc
These cases have only been discovered because Mothers have gone to Appeal, knowing and being able to prove that they gave birth to their Children, who have different DNA.
Men have also been unable to prove they are the Father by DNA testing.
Mark
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1746,
Thank you. I will watch it on my exercise bike for the next two mornings. Comments to follow. I hope this doesn't let a few villains off the hook.
Martin
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Mark, Interesting.
Googling it comes up with several articles attempting to explain it, but I am lost, haven't watched the programmes as yet, I am away from home tonight.
I don't understand how, if you absorb your twins DNA, why it turns out so different from parents' DNA - you could still only have 50% from each parent, couldn't you, therefore would match both of them?
Regards Margaret
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As I understand it, one version (at least) of chimerism happens as follows:
Sperm 1 fertilises Ovum A (genome 1/A)
Sperm 2 fertilises Ovum B (genome 2/B)
...which should create fraternal twins, but instead the two genomes are incorporated into a single foetus (chimera) who is therefore born with a double genome 1/A + 2/B. The different genomes may be expressed in different parts of the body.
So if a female chimera expresses 1/A in her ovaries and 2/B in her blood, a child of hers will have DNA consistent with a descendant of 1/A, but when the mother has a blood test it will show her as 2/B and therefore apparently not the mother of the child.
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Oh avm228
To put it in simple terms ... it means a Mother could have a DNA test and her child (born from her womb) could have a DNA test too, with the result that they are not related.
Very crudely, one of the parents seems to have a dual set of DNA, if the affected parent is tested they exhibit one set of DNA. But their child inherits the other.
Mark
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1746, I just watched the program, and it was truly remarkable. Anyone with an interest in DNA should watch it. The link further up this thread should be watched from 15:30. It is truly remarkable. The events of this article were reported by National Geographic Magazine 7 years ago.
I'm getting off-topic but one thing I really hate is celebrities who move out of their field of expertise and start doing something else, like pop stars climbing Kilimanjaro. Chris Packham is a well respected birdwatcher, but it did seem that the producers of this programme had spent longer attending to his personal grooming than actually producing the program. Gone is the common sense and factual straight presentation of 1960s Tomorrow's World, replaced by somebody of my own age who is starting to look very much like a well-groomed version of Johnny Rotten. This program does seem aimed at the sort of parents who can't be bothered to take an encyclopedia down from the shelf, ( assuming they even have a one volume encyclopaedia) or to take their children pond dipping. We do seem to be breeding a generation of Media-friendly teenagers, who can pull all the right faces, but let themselves down when they open their mouths and gibberish comes out.
Martin
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Hi all
So are we now saying it's possible for a child to take a DNA test then their parents and then the results show no links between them ???
Makes me think twice about getting my test done ;)
BourneGooner
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That's what I have read. Only 30 cases are recorded though.
Martin
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That's what I have read. Only 30 cases are recorded though.
Martin
But these cases are likely some (or all) of those which have gone to a Benefits / Paternity Appeal.
I wonder what the total of those who have been tested for this specific condition are?
Some more data would be interesting!
Rootschatter Guy Etchells, noted this lady with Genetic Chimera in a reply on another thread, but it didn't seem to get noticed.
http://www.rootschat.com/forum/index.php?topic=745625.msg5930749#msg5930749
Mark
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1746, I just watched the program, and it was truly remarkable. Anyone with an interest in DNA should watch it. The link further up this thread should be watched from 15:30. It is truly remarkable. The events of this article were reported by National Geographic Magazine 7 years ago.
Hello Martin and All
I couldn't believe what I was hearing, whilst at the same I'm recently being bombarded by adverts and emails to take various DNA Tests for family tracing purposes.
Mark
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Appears it can also happen to fathers as well!
https://www.medicaldaily.com/human-chimera-paternity-test-reveals-child-fathered-long-lost-vanished-twin-absorbed-359050
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Hello
Thank you, interesting that link!
Yes, information says a Father too, can be affected by extra DNA.
His Child's DNA then shows no match to his DNA.
Claims of other transfer too.
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Good job I applied for yet another Will (looking at the notebooks it must be over 100 Wills seen, trying to make an ancestor link) ???
Mark
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Genetically is showed the father as the child's uncle and presumably this would also be the case for a women and the child would show as the mothers niece/nephew. In the Fairchild case the grandmother still tested as genetically the children's grandmother!
Nobody can really know how prevalent genetic chimerism without more DNA testing.
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How often in real life do we know of examples where the child is the offspring of an uncle or where grandpa is the daddy and everyone involved goes into denial? With as common as the problem is, I think I'd believe the DNA test as people do have reasons to lie.
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Well well well
xin :o :o :o :o :o
This similar idea was on Criminal minds or CSI some years ago... two types of DNA for some reason I cannot recollect it all now.. BUT there you go ... NOTHING is Definite ---- or is it :-[ ::)
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That's what I have read. Only 30 cases are recorded though.
Martin
Sorry but that was the figure for the USA in 2008 there are 100 confirmed cases so far but most cases of chimerism go through life under the radar, it is possible (though unlikely) that many of us are chimeras, but with the popularity of DNA testing increasing who knows what the future holds.
On study suggests 1 in 10 cases of twins and 1 in 5 of triplets.
Though chimerism stemming from a lost twin (tetragametic chimerism) produces the most extreme form fraternal twins can also have the condition due to them exchanging chromosomes.
A baby can acquire some of the mother's DNA, in a condition known as microchimerism and the mother can also acquire some of her baby’s DNA in her bloodstream.
It should also be noted that chimerism is not a single condition there are many forms of chimerism in humans and even more in nature.
This is one of a number of reasons why I do not believe the claims made by many DNA companies and by zealots of DNA
Cheers
Guy
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Is chimerism a theory or proven fact? According to this report there are 28,000 babies switched at birth per year! How do we know that the babies tested in the chimerism tests weren't switched babies? https://brandongaille.com/20-babies-switched-at-birth-statistics/ And that still can't rule-out the mid-night creep, how many times will we have to hear the "I did not have sex with that person"? I trust science more than I trust people, especially when their mouths are moving.
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Is chimerism a theory or proven fact? According to this report there are 28,000 babies switched at birth per year! How do we know that the babies tested in the chimerism tests weren't switched babies? https://brandongaille.com/20-babies-switched-at-birth-statistics/ And that still can't rule-out the mid-night creep, how many times will we have to hear the "I did not have sex with that person"? I trust science more than I trust people, especially when their mouths are moving.
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I think it's a fact. In the Lydia Fairchild case her DNA didn't match her children, despite proof that she gave birth to them and her partner was the father. It was later proved that she carried two different DNA. Her hair and nails were one set of DNA and a cervical smear was a different set of DNA. The cervical DNA did match her children.
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There is known evidence of cross-contamination in hair and nail DNA. I can understand why there may be a false DNA test of that material. But would a cheek swab be a different match than the cervical test? Any examples of that happening? So here again, science wins. As long as the test has real-live-uncontaminated DNA you get good real results.
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There is known evidence of cross-contamination in hair and nail DNA. I can understand why there may be a false DNA test of that material. But would a cheek swab be a different match than the cervical test? Any examples of that happening? So here again, science wins. As long as the test has real-live-uncontaminated DNA you get good real results.
In the case of Karen Keegan, whose case was instrumental in resolving the Lydia Fairchild case, they took swabs from her cheeks, as well as nails, hair and blood. None matched her sons, however they did further tissue tests from other parts of her body and found matches to her sons.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1808039/ This article has some information about both the Keegan and Fairchild cases.
Presumably there are lots of different outcomes from chimerism and lots of different types. If a grandparent was the chimera, DNA would match your parents, but may not match your grandparent! or brothers and sisters could appear to have a different parents, even though they don't. The possibilities may be endless!
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There is known evidence of cross-contamination in hair and nail DNA. I can understand why there may be a false DNA test of that material. But would a cheek swab be a different match than the cervical test? Any examples of that happening? So here again, science wins. As long as the test has real-live-uncontaminated DNA you get good real results.
A link (posted somewhere on this thread) goes to an article that claims scientifically, that DNA of another/others can be acquired from Blood Transfusion/s and Organ Transplant/s, so if the body does not reject either, then it is claimed you can aquire DNA by these procedures too.
Not against DNA Testing, but you need all the official Family History paperwork all checked and in order too :D
DNA testing is only one aid, to the family history researcher!
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Is chimerism a theory or proven fact? According to this report there are 28,000 babies switched at birth per year! How do we know that the babies tested in the chimerism tests weren't switched babies? https://brandongaille.com/20-babies-switched-at-birth-statistics/ And that still can't rule-out the mid-night creep, how many times will we have to hear the "I did not have sex with that person"? I trust science more than I trust people, especially when their mouths are moving.
You obviously have not read the details of the Fairchild case. Lydia Fairchild was a mother of 2 children, as she was claiming Government Assistance for these two children she was ordered to have a DNA test to prove that she was their mother, the DNA test appeared to show she could not be the mother of her two children.
Now facing criminal charges for fraud, Fairchild was ordered to have a court representative be present at the coming birth of her third child for an immediate DNA test, which revealed the same results, she could not be the mother of the child the court official witnessed being born by her.
The disgrace of this is in 1953 a human chimera was reported in the British Medical Journal.
A 1996 study in USA found that such blood group chimerism is not rare.
See-
Van Dijk, B. A.; Boomsma, D. I.; De Man, A. J. (1996). "Blood group chimerism in human multiple births is not rare". American Journal of Medical Genetics. 61 (3): 264–8.
Cheers
Guy
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Genetic Chimerism
After DNA testing in Benefit and other challanges in the United States, 30 cases in the US have uncovered Chimerism.
It seemed to begin when Lydia Fairchild tried to claim her child benefit for her three children and she was refused. In the US when claiming benefit for children it was necessary for the Claimant and Children to have a DNA Test.
A second DNA test of Lydia and her children also confirmed her three children were not her children, according to DNA testing.
The Case was Appealed.
It has been discovered that when the fetus was in the womb, the development process had begun with twins early on, but the twin's DNA had been absorbed into the other surviving fetus.
The Mother having a DNA test, has the different DNA of her fetus twin (the twin which never developed).
Her children she gave birth to, have other DNA!!
Other cases have been appealed and also made the subject of scientific analysis and investigation and 30 cases in the US have been found of Chimera.
Mark
This is no opinion, because this case was appealed through the US Courts and subject to scientific investigation and analysis too.
During an Appeal process, I had heard that a child's DNA was found in the child's Grandmother.
However, the child had no DNA from the Birth Mother.
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So if your DNA Test is not a match with your Birth Mother's, Father's, your Twin's or other family DNA, DON'T make assumptions and allegations in your family that could affect your Parents reputation or start a family feud or fall out!
There may be a scientific reason why your DNA does not match your Birth Mum's / Birth Father's DNA Test!
Mark
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This is no opinion, because this case was appealed through the US Courts and subject to scientific investigation and analysis too.
During an Appeal process, I had heard that a child's DNA was found in the child's Grandmother.
However, the child had no DNA from the Birth Mother.
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So if your DNA Test is not a match with your Birth Mother's, Father's, your Twin's or other family DNA, DON'T make assumptions and allegations in your family that could affect your Parents reputation or start a family feud or fall out!
There may be a scientific reason why your DNA does not match your Birth Mum's / Birth Father's DNA Test!
Mark
Sound advice - it just shows you can never be sure!
The Fairchild children did match to other tissue samples from their mother, as did the Keegan children, but not the original samples that were taken. The way I interpret it is that both of these mothers had two distinct sets of DNA, but passed only one to their children.
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The way I understand this chimera effect is that an animal can have more than 1 DNA but that DNA is going to match some relative. It is not going to be a full spanking brand-new match to a never before existing being. The DNA going to match an implant or a transplant or something that is traceable to something/someone known. Am I correct on this?
Not too worried about getting the family upset about this topic. It's outright kind compared to what I've heard.
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The way I understand this chimera effect is that an animal can have more than 1 DNA but that DNA is going to match some relative. It is not going to be a full spanking brand-new match to a never before existing being. The DNA going to match an implant or a transplant or something that is traceable to something/someone known. Am I correct on this?
Not too worried about getting the family upset about this topic. It's outright kind compared to what I've heard.
Yes that is correct but what you may be missing is the DNA taken from the child may not match the DNA from either of their biological parents.
In other words if a parent is a chimera then they have two sets of DNA rather than one and depending on what parent of their body was tested it may not contain the DNA transferred to their biological child.
Cheers
Guy