Posted on 11/17/2003 10:20:10 AM PST by NYer
One human chimera came to light when a 52-year-old woman demanded an explanation from doctors after tests showed that two of her three grown-up sons were biologically unrelated to her.
Although the woman, "Jane", conceived them naturally with her husband, tests to see if she could donate a kidney suggested that somehow she had given birth to somebody else's children.
A study in the New England Journal of Medicine by Dr Margot Kruskall, of the Beth Israel Deaconess Medical Centre in Boston, Massachusetts, showed that Jane is a chimera, a mixture of two individuals - non-identical twin sisters - whose cells intermingled in the womb and grew into a single body.
Dr Kruskall believes the most likely explanation is that Jane's mother conceived non-identical twin girls, who fused at an early stage of the pregnancy to form a single embryo, according to a report published today in New Scientist.
For some reason, cells from only one twin dominate in Jane's blood - used for tissue-typing. In her other tissues, however, including her ovaries, cells of both twins live amicably alongside each other, hence the apparently impossible genetics of her three sons.
One son came from an egg derived from the twin whose cells dominate Jane's blood, while his brothers came from eggs derived from the other twin's cells.
Around 30 similar instances of chimerism have been reported, and there are probably many more who will never discover their unusual origins. Most chimeras probably go through life unaware of their unusual constitution.
So I guess you could end up with a false negative. It would be pretty rare, though...we need to know how rare.
My point was entirely on the topic of whether her sons are "biologically related"
Chimerism, the presence of two genetically distinct cell lines in an organism, either is acquired through the infusion of allogeneic hematopoietic cells during transplantation1 or transfusion2 or is inherited. In fraternal twins, chimerism occurs by means of blood-vessel anastomoses. A less common cause of congenital chimerism — so-called tetragametic chimerism — occurs through the fertilization of two ova by two spermatozoa, followed by the fusion of the zygotes and the development of an organism with intermingled cell lines.3 Examples have been found in mice4 and other mammalian species,5,6,7 including humans.8.
Oops, my bad....in her case it is the head of a serpent, body of a goat and tail of a lion... what do they call that "mythology"????
And the legs of a hippo...
Not me. Biology is icky and complicated. I always skip the biology ones in Scientific American. I'm only smart enuf to do rocket science!
--Boris
I'm glad to see I wasn't completely out of my head hearing this.
It's really fascinating.
Sorry but that theory was disproven a long time ago.
Because He said.
My answer wasn't "Because". It was "Because He said."
Let me restate my response.
Because HE said.
I'm not sure why you are having a hard time grasping this.
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