Genetic Chimerism - DNA Testing Might Not Show Match Between a Parent & Child

[BushInn1746]

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

[Mart 'n' Al]

I'd like to know more about "... the twins' DNA had been absorbed into the other surviving foetus."

Martin

[BushInn1746]

Hello Martin

The case has been mentioned on BBC 2 presented by Chris Packham, the 'World's Weirdest Events'.

Mark

[BushInn1746]

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

[Mart 'n' Al]

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

[sugarfizzle]

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

[avm228]

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.

[BushInn1746]

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

[Mart 'n' Al]

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