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The Not-So-Legendary Chimera

Article #117 • Written by Cynthia Wood

Imagine if you discovered one day that two of your three children were genetically not yours. Recriminations, marital troubles, perhaps a divorce, right? Now add a twist. What if you were these children’s mother? Suddenly the question becomes not “Who?” but rather “Huh?”

Yet that’s what happened to “Jane”. At the age of 52 when her children were full-grown, she and her children underwent genetic testing for a possible kidney transplant. Completely unexpectedly, two of her three children tested as genetically not hers. A mix-up of babies was ruled out, and she and her husband had not undergone in vitro fertilization, so it was absolute that her children were hers.

Jane, it turns out, is a human Chimera.

The Chimera is primarily known as a creature of Greek legend – a fire-breathing monster with parts of a goat and a lion with a serpent for a tail. In biology the term has come to refer to any organism that contains more than one set of genes. There are chimera African violets, where the core of the plant is genetically distinct from the outer layers. Animal chimeras, or mosaics, as they can also be called, don’t usually divide so neatly.

The most common form of human chimera is called a blood chimera. This happens when fraternal twins share some portion of the same placenta. Blood and blood-forming tissue is exchanged, and takes up residence in the bone marrow. Each twin is genetically separate except for their blood, which has two distinct sets of genes, and even two distinct blood types. Up to 8% of fraternal twins are blood chimeras, and as the incidence of fraternal twins in the general populace increases with the popularity of in vitro fertilization, the number of blood chimeras should rise proportionately.

What happened to Jane is a much rarer. Rather than a simple exchange of blood, she and her fraternal twin merged in utero, leaving only one fetus. The cells in her body are a mosaic of genes from both of the original embryos. The cheek cells from which the genetic testing was done were from one of those embryos, but at least some of the cells in her ovaries came from the other. Interestingly this genetic oddity gives her a better-than-usual chance of having a successful kidney donation, as her immune system does not reject as foreign either of two distinct tissue types. She would, however, be a poor candidate as a kidney donor were she in that position, due to the likelihood of two tissue types being present in her kidneys.

Many human chimeras show no overt signs of their condition. Others have more obvious physical findings. Doctors at the University of Edinburgh in 1998 had a patient referred to them for an undescended left testicle. However, when they examined him they could not find a second testicle. Instead they found something quite unexpected, an ovary and a fallopian tube. Their patient was a chimera formed from the fusion of male and female embryos. While this is a dramatic finding, most chimeras show more subtle signs, such as mismatched eyes, or parti-colored hair.

This sort of mosaicism is exceedingly rare in the medical annals, though not completely unheard of. To date approximately thirty cases have been found world-wide. However, most chimeras are unaware of their condition until some anomaly brings it to light. Given that, it is entirely possible that there are many more chimeras in existence. After all, in the case of Jane had the genetic anomaly shown up in the father rather than the mother, it is not only possible, but probable, that the first obvious explanation would have been the only one looked at, and the marriage would have ended up in divorce court rather than the New England Journal of Medicine.

Article written by Cynthia Wood, published on 15 February 2006. Cynthia is a contributing editor for DamnInteresting.com.

Edited by Alan Bellows.

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63 Comments
knightrider
Posted 15 February 2006 at 01:53 pm

I wonder how they ruled out the babies being switched?


indra c
Posted 15 February 2006 at 01:57 pm

Wow. It calls back the discussion we had on the "History's Youngest Mother" article from a couple months back. This could be a possible loop-hole which would allow self impregnation in human beings. Great one Cynthia.

So does this make David Bowie a human Chimera? Does this also apply to Huskies which often have different colored eyes?


Scott Bowers
Posted 15 February 2006 at 02:20 pm

If I remember my high school biology right, people with both sets of sex organs (hermaphrodites) are usually either sterile or female-sterile. So self impregnation is unlikely, but not impossible.

I'd also like to know how they ruled out the possibility of the babies being switched? I supposed she could have given birth at home instead of a hospital, so that's one possibility.


Robert Waugh
Posted 15 February 2006 at 02:42 pm

knightrider said: "I wonder how they ruled out the babies being switched?"

They would still have the same father, and his genes. That's my guess.


Ultraformat
Posted 15 February 2006 at 02:46 pm

This is the defense that cyclist Tyler Hamilton is using to beat the accusations of blood doping.


BarryW
Posted 15 February 2006 at 03:22 pm

...and Tyler recently lost that appeal.


Joshua
Posted 15 February 2006 at 03:36 pm

Wouldn't the chimera phenomenon also complicate the use of DNA evidence in forensics? The problem in this case would be false negatives (i.e. chimeric guilty parties getting away with their crimes because of DNA mismatches), which also casts doubt upon the ongoing Innocence Project.


mrjondoe
Posted 15 February 2006 at 04:06 pm

joshua,
there is a CSI that talks about this, not to say that CSI is an expert source for forensics facts, but they get a different set of DNA from his cheek swabs and his blood. its an interesting episode to say the least


Secret Ninja
Posted 15 February 2006 at 04:54 pm

I think huskies eyes are different colors because the gene is co-dominant.


clayton
Posted 15 February 2006 at 05:24 pm

I saw a segment about this on Discovery about 6 months ago. Same story, different women. They showed some of the different scientific evidence the scientists had. One characteristic of human chimeras was that there bodies were covered in checker-board patterns all over their bodies. I can't seem to find any pictures of human chimeras but here is a picture of a chimera orange[fruit].

http://zimmer.csufresno.edu/~earlb/chimera.htm


white_matter
Posted 15 February 2006 at 06:51 pm

I wonder what role (if any) this condition would play in psychological issues i.e. multipule personality disorder.

It sounds like a bad movie, I know, but I wonder if it has any bearing...


Marius
Posted 16 February 2006 at 04:22 am

Joshua said: "Wouldn't the chimera phenomenon also complicate the use of DNA evidence in forensics? The problem in this case would be false negatives (i.e. chimeric guilty parties getting away with their crimes because of DNA mismatches), which also casts doubt upon the ongoing Innocence Project."

I would imagine that this is a rare enough phenomenon that it would not significantly affect the accuracy of DNA testing, and even if it did it sounds simple enough to test for it. I'd be interested to see if any long term studies have been done on offspring of chimeras. Perhaps this is just another of nature's ways of ensuring genetic diversity in small populations.


JustAnotherName
Posted 16 February 2006 at 07:35 am

Excellent article. Darn that I missed that CSI. As stated, it is not a TV Show where forensics is an experts source, but it would have stirred enough interest for me that I would have looked into it on the Internet, send it to my cousin, and have him explain the Medical Journal information for me. I come to this site to read information in terms I can grasp; I usually do not go into the actual medical journal information. That is my cousins job.


petedotnu
Posted 16 February 2006 at 07:47 am

indra c: Bowie's eyes are mismatched as a result of a fight that he had at school, not a genetic condition.


AviDardik
Posted 16 February 2006 at 02:10 pm

I thought this was digg-worthy, so I posted it.
Apparently I was right, you just made the front page.. again.. ;-)


dysan
Posted 16 February 2006 at 02:29 pm

I saw a show recently on this. I think it was the same person. The courts were going to take her children away as they wern't geneticly hers, except she had given birth to them. She found out about this condition and got the judge to grant a contiuace as she was pregnant at the time.

The other thing the don't mention is that the "other mother's" DNA was related to Jane as a sister. Doing some genetic testing all the missing genes were found in her brother. I think her parents might have been dead, but I'm not positive.


Bryan Lowder
Posted 17 February 2006 at 02:50 pm

Fascinating article, Cynthia. Don't forget that all human females are mosaics, too, with portions of their bodies expressing one X chromosome, and other portions expressing the other. I recall a biology class showing photos of women who had been smeared with a yellow substance that turns black when wet. One of their X-chromosomes could express sweat glands, the other couldn't. After a little excercise, large irregular swaths and patches of black appeared. I also heard that tortiseshell cats (always female) appear the way they do because their X-chromosomes carry different fur colors. And the retinas of partly-colorblind women show a mosaic of colorblind and color-sensitive patches. Of course, your story is about something dramatically different, but it's weird to think that every woman is genetically two people.


desertfriedjeep
Posted 17 February 2006 at 10:50 pm

I wonder if this could be the origin of the story of the "virgin birth" of Jesus. Could Mary have been self fertile? Maybe though I just need a nap or another cup of coffee. :)


hawkwatcher
Posted 18 February 2006 at 10:57 am

The show was CSI:LasVegas with Gil Grissom. He was sure the guy raped and murdered a woman, but the semen sample together with the check swab from the suspect showed a possible DNA match for a brother he didn't have. When Gil was taking flash pictures of the suspect's back, there was a distinct after image on his back. After his usual tenacious research was finished, he confronted the man with his conclusions. The man admitted he knew he was a chimera because of a failed transplant that should have taken. I found this fascinating.


Cynthia Wood
Posted 18 February 2006 at 11:44 pm

Dysan - not the same woman, though very similar in some details. Jane's children were grown at the time of the testing, so she was in no danger of losing custody.

Thanks AviDardik!

Bryan - I had completely forgotten that tidbit (not surprising as I think I last heard it about 20 years ago). Fascinating. It makes me wonder about my own gene expression.


sharon
Posted 06 March 2006 at 04:57 pm

A very interesting article Celia, having just watched the programme that appears to be the one Dyson spoke of I sought more information.. The maternity case was proven in the end when the woman gave birth to her third baby, both mother and baby were tested immediately after the birth and the DNA tests indicated that she was NOT the mother, which of course was impossible. The conclusion, I believe, was that the blood carried one type of DNA but separate hairs can contain the 2 types of Dna, and organs can contain tissue with both types of DNA but one type being more prevalent than the other. Scarey stuff as suggested above where guilty parties can be tested as not guilty in some cases. One worry for me is the home DNA tests that are available and the statistics they claim as accurate, sure there may have been some divorces as results that the tests showed that the father was not a true parent when he was, and also cases where the father wanted custody but DNA tests have shown him not to be the father when he was.


Chory
Posted 12 March 2006 at 06:55 pm

Bryan Lowder said: "Fascinating article, Cynthia. Don't forget that all human females are mosaics, too, with portions of their bodies expressing one X chromosome, and other portions expressing the other. I recall a biology class showing photos of women who had been smeared with a yellow substance that turns black when wet. One of their X-chromosomes could express sweat glands, the other couldn't. After a little excercise, large irregular swaths and patches of black appeared. I also heard that tortiseshell cats (always female) appear the way they do because their X-chromosomes carry different fur colors. And the retinas of partly-colorblind women show a mosaic of colorblind and color-sensitive patches. Of course, your story is about something dramatically different, but it's weird to think that every woman is genetically two people."

I'm sorry, but as a High School student I could debate this. From my understanding (I am 99% sure I am correct) all of a female's cells, except of course her eggs, are diploid, having both X chromosomes, one from each parent. The only reason for it to be otherwise is if said female has Turner syndrome (only one sex chromosome, obviously X) or Poly-X. There may be other syndromes, but those are the only ones I know of. But in a normal XX human being, normal body cells have BOTH (two) X chromosomes. The only cells that do not have both are the haploid sex cells produced by that individual's ovaries. Those cells only have one or the other. That said, I do not see how all human females are mosaics, as you say.

The other problem I have with your statement - how can someone be partly colorblind? Colorblindness is a sex linked reccessive disorder. Therefore the only possible way for a woman to be colorblind at all is for both her X chromosomes to be reccessive for colorblindness. Remember punnet squares? Her father has to be colorblind for her to be as well, and her mother must be at least a carrier. If her mother is heterozygous, her mother will not be colorblind, but rather will show a normal phenotype.

The phenomenon of a chimera could change that, but my understanding is that you are either colorblind or you are not.


kev23777
Posted 29 March 2006 at 07:30 am

Chory said: "I'm sorry, but as a High School student I could debate this. From my understanding (I am 99% sure I am correct) all of a female's cells, except of course her eggs, are diploid, having both X chromosomes, one from each parent. The only reason for it to be otherwise is if said female has Turner syndrome (only one sex chromosome, obviously X) or Poly-X. There may be other syndromes, but those are the only ones I know of. But in a normal XX human being, normal body cells have BOTH (two) X chromosomes. The only cells that do not have both are the haploid sex cells produced by that individual's ovaries. Those cells only have one or the other. That said, I do not see how all human females are mosaics, as you say."

You are correct to a certain extent when you say that all cells are diploid, except for sex cells, but the second X chromosome in females is tightly compacted and inactive. Thus different regions of a woman's skin, and the rest of here body for that matter, can be made up of cells that effectively have different X chromosomes. The inactive X chromosome is called a Barr body.

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/S/SexChromosomes.html
Contains information on Barr bodies, scroll down to "X-Inactivation".

I learned about this in a College Biology class.


NewEvolution
Posted 29 March 2006 at 10:45 pm

knightrider said: "I wonder how they ruled out the babies being switched?"

While the cells tested in the mother's cheek didn't match her children, the cells derived from the other DNA present in her would. It just so happened that the eggs that formed those few children had different DNA than the spot tested. She still matches those children genetically, just not all over.


Chory
Posted 11 April 2006 at 05:11 pm

kev23777, that is very interesting... do you know any other sources of more information? I would like to know more, but I don't want to clutter up this comments place on a semi-unrelated topic.


Elle it is k
Posted 19 April 2006 at 07:39 am

mrjondoe said: "joshua,

there is a CSI that talks about this, not to say that CSI is an expert source for forensics facts, but they get a different set of DNA from his cheek swabs and his blood. its an interesting episode to say the least"

yeah that was a good episode..I'd never heard of it before I saw it.


aprilgrandma
Posted 26 April 2006 at 11:39 am

April 26,2006

The CSI was the reason I looked the subject up. This is absolutely fascinating.
or blind people
Byran- I am a color blind female, most peole don't realize that color blind people do see some color. Mine is all but blue, black, and brown. Thats how some people get partial color blindness. I know it is a pain,especially with children and matching clothes


Twinb1953
Posted 27 April 2006 at 09:56 am

I saw the documentary regarding chimeras. It was on last night. It is called, "The Twin Inside Me". It focuses on the stories of two woman who discovered through life events that they were chimeric. Their names are Karen Keegan and Lydia Fairchild. It was a fascinating show. I would highly recommend it. The implications are very scary, however. I wonder how many innocent people have been convicted, and coversely, how many guilty people have escaped punishment because of DNA testing.
Twinb1953


donnajean
Posted 27 April 2006 at 02:19 pm

I think I watched the same show. It was called "I Am My Own Twin." Scientists were able to match Karen's sons to Karen's brother. They said the boys could be the sons of Karen's husband and her brother! Anyway, once they found the genetic strain in the family, they knew the sons were biologically Karen's, so they kept testing DNA from different areas/organs of her body. They were unable to find a match from readily available samples (hair, blood, skin, etc.) Ultimately, they found some stored samples of internal organs from surgeries/biopsies that she had, and found a genetic match to the sons in those. I wonder if you receive a blood transfusion, you become a created chimera? The transfused blood cells do reproduce, don't they?

donnajean


Cori
Posted 30 April 2006 at 11:24 am

An episode of Law and Order: Special Victims Unit had a created chimera. A rapist had left a smear of blood in a victim's home, but the suspect's cheek swab didn't match. However, all of the other evidence pointed to him. Elliot got his medical records, and it turned out that he had received a bone marrow transplant in college. His blood had different DNA than the rest of him. Interesting stuff.


HollyRock
Posted 15 September 2006 at 08:12 am

I never post on sites, but I just have to in this case. The other day I was trying to rember what the name for learning about something, and then hearing it shortly after was. So then I find myself reading Dam Interesting at work as usual, and I come across the article for baader-meinhof. Wich was cool, but now in case I'm starting to lose y'all I'll bring it right around to this article. This tuesday a new House comes on, and not to far into it I've totally figured it out from reading the above article about Chimeras the same day. At first it looks like they don't go there so I start to get bummed out, then of course House solves it and saves the day. It was a good episode and like the nerd I am I've been excited all week. I just love this web site! Any one intrested in this should watch it, and besides it has aliens, a chimera, and Laura Palmer! Where can you go wrong.


Dottie1985
Posted 02 October 2006 at 02:42 pm

I seen the same show on discovery health that Clayton has mentioned seeing and I recall the the one lady on the show that had two children and was pregnant with her 3rd, her and her boyfriend had split up so she wanted to get help from the state so that she could support her kids easier...but of course in the state that they were in they made her, her kids, and their father go for DNA testing...it turned out that he was the father but the tests showed that there was no possible way that she was the mother of the children. The father testified to being in the room when the children were born and that he seen her give birth to those children. She ended up in court over the whole ordeal because the state thought that maybe the man had the children with one of her sisters or something and that they were trying to pull a fast one. So she had gone to court and they didn't believe a word that she said so when she finally went into labor with her last child one of the witnesses for the state was in the delivery room and when the baby ws born they did a test on him as well...that showed the same results. But there are so many ways to tell of Chimerism such as looking at the red blood cells...I'm not sure of the other tests because I haven't had the time to research Chimerism as much as I would like to...but I guess the way that they rule out the children being switched is if the father appears to be the father of all the children, I mean how big of a coincidence would it be that there was a women in the same hospital giving birth to the same man's child at the same time EVERYTIME?


sweety_muse.
Posted 07 October 2006 at 05:01 am

Hi :-)
I saw that programme,thought that it was scary interesting and that woman chimera got all my sympaty and understanding for her struggle ...
Then some time past on..

I've almost forgotten about the tv-programme ,when I got very sick and was put in hospital for Mononnucleose with a lot of other sickness within or rather because of it I became very sick with other symptoms (hard to decribe in english)..
I should have taken a lot of bloodexamples during my stay and after because the doctor's needed to see or rather follow my illness.
Then an ODD thing happened:

From one side of my body the bloodexamples tells that I have (had?) got the disease..

From the other side of my body the examples say's that I don't..

That's been about three week's ago..

I must tell you all that my mother expected twins when she was pregnant...
I have never been bloodtransfused..

Am I a Chimera I wonder????

Why do my bloodexamples tells two different versions?

My doctor say's that my blood "disagrees".....

Is that correct
or????

I have two different colours in my eyes (brown and blue)...

If one of you out there reads this please inform me because maybe,- just maybe......

I'm a Chimera ???

Regards from louise in Denmark


pantsman
Posted 14 December 2006 at 10:03 am

AAaargh, Baader-Meinhof Phenomenon!

I just finished reading a book yesterday where the evildoer was a chimera. (Greg Bear, Quantico)

And now I read some old DI article and here it is.


Starling
Posted 10 February 2007 at 08:23 am

Very interesting article, I've never heard of this before. Thanks, now I have something else to ramble on about when I'm bored. xD My friends will kill you...


FireDude
Posted 10 February 2007 at 08:50 am

donnajean said: "I wonder if you receive a blood transfusion, you become a created chimera? The transfused blood cells do reproduce, don't they?"

Blood cells do not reproduce. All blood cells originate in bone marrow. So a blood transfusion would only cause you to be a blood chimera until all the tranfused cells die off (I think maybe a couple months, but not sure). On the other hand, as Cori states, after a bone marrow transplant, you will be a blood chimera.


aibhric
Posted 15 February 2007 at 08:00 am

i think the question with this is how rear is it really? Could this not be more common than we think it is?


curiouser&curiouser
Posted 22 March 2007 at 01:05 am

I taped "I Am My Own Twin" because it was so fascinating. It brought up an intriguing possibility. If twins are conceived and one is, for whatever reason, "absorbed" into the other, could this be the ultimate cause of homosexuality? Bear with me here. Assume a male and a female are conceived and the female embryo merges with the male embryo. A male is born. All through his life he feels he is a woman trapped in a man's body. (A common statement heard from gay men and women.) Even though his body is male could it be possible for the "femaleness" of the merged embryo to have survived long enough after merging to be dominant in regards to the psychological gender/inclinations of the male? If this theory could be proved beyond a doubt then homosexually-inclined people would be basically a third (or fourth) "gender". They would be no more responsible for their mannerisms or inclinations as anyone would be for their natural hair or eye color. Boy, the polititians, insurance companies and holy rollers would would go NUTS! Gay marriages would have to be allowed, thus, as spouses, insurance companies couldn't discriminate against them, and the churchies would have to accept the fact that they are the way they are because GOD made them that way and there is nothing "wrong" with them. I need to find someone who studies homosexuality and genetics!


Sheila
Posted 24 March 2007 at 02:29 am

Curiouser

I am so glad to know that others have come to that same question about homosexuality/bisexuality, I personally believe it to be a strong reason. And yes, it would be nice to see the "Holier than Thou" croud knocked off their pulpit a bit.


misanthrope
Posted 26 March 2007 at 06:46 am

curiouser&curiouser said: A male is born. All through his life he feels he is a woman trapped in a man's body. (A common statement heard from gay men )

Is it? or are you confusing transgenderism for homosexuality? None of the people I know who are gay want to be the other sex, they just don't feel "that way" about them. Statistics of a small sample, I know, but stil...


ref
Posted 17 April 2007 at 02:40 pm

I had to become a part of this discussion because I also saw the Discovery Channel show and got a huge shock when they showed the image of the body with two different pigmentations, divided in the middle, I have the same thing! My torso is almost exactly divided down the middle from my upper chest to my waist and around under my arm and on my back, also exactly to the center. I have always thought it was a big birthmark and I was initially freaked out to think that I was two people in one!
Then I started thinking about how when I was a kid and our whole family was together, I often had a feeling that someone was missing. . .I'm not joking.
Anyone else know of someone with a half and half body?


kopetie
Posted 30 April 2007 at 06:47 pm

ref said: "I had to become a part of this discussion because I also saw the Discovery Channel show and got a huge shock when they showed the image of the body with two different pigmentations, divided in the middle, I have the same thing! My torso is almost exactly divided down the middle from my upper chest to my waist and around under my arm and on my back, also exactly to the center. I have always thought it was a big birthmark and I was initially freaked out to think that I was two people in one!

Then I started thinking about how when I was a kid and our whole family was together, I often had a feeling that someone was missing. . .I'm not joking.
Anyone else know of someone with a half and half body?"

I saw the Discovery show as well... and it made wonder about my own DNA. I have a very clear line running down the inside of my legs dividing my front from my back, with the skin on my back darker than the front. I also have green eyes with brown areas. Makes me wonder, but I haven't been able to find much information.


illumi83
Posted 25 June 2007 at 04:11 am

When I read this, I am thinking about this: how many REAL fathers might have been excluded in paternity tests, and sent home by the judge.? How many murderers might have been sent home by a judge because of the SO RELIABLE dna testing! If there is only the slightest chance of chimerism, they don`t take it serious enough! In my eyes they should go after this more seriously and involve it in every dna test(in my eyes it shouldn`t matter how long it takes)! Even if 0,1% or 0,01% of the world population are chimeras. in my eyes this is still a huge number of people, to take it more serious!

I have a 6 year old son, and i know that he is the only possible father! he was excluded in the test!
I know he is my sons daddy, there was nobody else in those 2 years we were together!
What if he is also a chimera? I will never be able to afford going after this because Dna is so reliable!
My Son lost his Daddy because its so rare they don`t take it serious( and he wasn`t able to handle the results).......what a shame!


illumi83
Posted 25 June 2007 at 07:19 am

And this is what i got off of the usa leading paternity testing laboraty!

Chimeras and mutations are not realistic answers. There are too many exclusions for it to be from mutations, and the likelihood of a chimera is so low that it makes it unrealistic to assume that happened.

Kim Gorman

PTC Laboratories
300 Portland Street
Columbia, MO 65201
573-442-9948
kim@ptclabs.com


Timmy j
Posted 10 August 2007 at 08:58 pm

Twelve years ago I was contacted by an ex girlfriend, Maria who wanted to see if I was the father of her 18 m/o daughter. I gladly took the paternity test, which excluded me as the father. There were two potential fathers, and the Maria had assumed that the other guy was the father, until Marias' grandmother pointed out that the child looked more like me than it did aether Maria or the other guy. By the time she contacted me, they were so sure the child was mine that they didn't bother to test the other guy, and when the test proved negative, everyone just said oh well the child must be the other guy's. It was a very trying and disappointing experience for me because as we awaited the test results I had begun to really look forward to being her father.
So, about ten years passed by without much thought about it, (other than having fond memory's of the brief time Maria and I were together), when I too watched the discovery show about chimeras'. It was like being hit by lightning! I had always wondered where my “extra nipples” came from! (they are symmetrical placed under my ribcage, and they look just like one of the pictures that they had on the Discovery show) I also have a tiny little growth inside my left nostril, and a tiny little extra ear hole on my right ear that occasionally secrets what must be inner ear fluid. Sense childhood I had always called them my extra ditty's, my extra nose, and my extra ear. Now I've learned of another physical sign of chimerism I have, which is that I grow very little facial hair on the right side of my face around my jaw. ( I guess the right side is my twin sisters face)
Now I'm desperately trying to track down Maria to ask her if she ever had the other guy tested. And I'm determined to get to the bottom of this.


Mz Criztale
Posted 13 August 2007 at 01:57 pm

I had to look up information on Chimera's because I was told by doctor's it was a posibiltiy that I might be one. Strange eh? I have two blood types. My mom fought for me in a custody battle when I was young and the court issued for a blood test. I was A+. When I had my kids I was tested as an O+. The only physical thing that I've noticed is that my eyes change colors. Haha though that might just be cliche it actually does happen. I have hazel eyes but they change to an icey blue. From my understanding my mom got pregnant with twins (both girls) but miscarried for one and my (then) fetus absorbed all the enzymes, blood type, dna, etc...leaving me the joy of telling people 'I am my own twin' haha! Pretty interesting I think!


tinwindows
Posted 02 November 2007 at 09:50 pm

curiouser&curiouser said: "I taped "I Am My Own Twin" because it was so fascinating. It brought up an intriguing possibility. If twins are conceived and one is, for whatever reason, "absorbed" into the other, could this be the ultimate cause of homosexuality? Bear with me here. Assume a male and a female are conceived and the female embryo merges with the male embryo. A male is born. All through his life he feels he is a woman trapped in a man's body. (A common statement heard from gay men and women.) Even though his body is male could it be possible for the "femaleness" of the merged embryo to have survived long enough after merging to be dominant in regards to the psychological gender/inclinations of the male? If this theory could be proved beyond a doubt then homosexually-inclined people would be basically a third (or fourth) "gender". They would be no more responsible for their mannerisms or inclinations as anyone would be for their natural hair or eye color. Boy, the polititians, insurance companies and holy rollers would would go NUTS! Gay marriages would have to be allowed, thus, as spouses, insurance companies couldn't discriminate against them, and the churchies would have to accept the fact that they are the way they are because GOD made them that way and there is nothing "wrong" with them. I need to find someone who studies homosexuality and genetics!"

I was talking to a friend about this same thing tonight and so looked for and found the stats for how many births actually begin as twins...and will post it below. I hope someone will find it useful.

the site : http://www.tachyonlabs.com/ultrasnd.html

and the story : ---------- begin excerpt from The New Yorker ----------

With the increasing use of ultrasound to detect early pregnancies, we now know that twinning is a far more common occurrence than anyone had previously imagined. Although only about one out of eighty or ninety live births produces twins, at least one-eighth of all natural pregnancies begin as twins. Many of us singletons, in other words, began life as something more -- as part of a pair.

Doctors equipped with color-Doppler and vaginal ultrasounds and high-speed scanners have been able to observe multiple pregnancies as early as five weeks after conception. "People are picking up twin pregnancies the size of garden peas," says Professor Charles E. Boklage, a developmental biologist at the East Carolina University School of Medicine and a well-known maverick in the world of twin biology. "They're seeing a lot more twins than they ever knew were there." Many doctors have undergone the unnerving experience of spotting twin embryos one month, only to find a singleton the next time they looked. What was happening? At the Third International Congress on Twin Studies, held in Jerusalem in 1980, this question was raised, and one of the participants cried out, "Vanishing twins!" -- thus giving a name to a phenomenon that has caused as much confusion as excitement.

Boklage studied reports of three hundred and twenty-five twin pregnancies and found that sixty-one ended as twins, a hundred and twenty-five as singletons, and the remainder -- a hundred and eighty-six -- as a complete loss: a reminder of how risky twin pregnancies are. Often the only external sign of a vanishing twin is vaginal bleeding. "The so-called phenomenon of the 'vanishing-twin syndrome' is neither phenomenal or a syndrome," Boklage contends. "It is much too common to be considered phenomenal, and it occurs for too many reasons to be considered any kind of syndrome." He says that most pregnancies, whether multiple or single, fail anyway, so it is not as surprising as it seems that twins often disappear. "Somewhere in the vicinity of ten to fifteen percent of us -- and that's a minimum estimate -- are walking around thinking we're singletons when in fact we're only the big half," Boklage says. He estimates that for every set of twins born live there are at least six singletons who are survivors of twin conceptions.

---------- end excerpt from The New Yorker ----------

Sharon J.


sugangl608
Posted 03 November 2007 at 11:54 am

I was recently watching a Discovery Health documentation on chimera's. It's pretty interesting. I am an identical twin, so after constantly being asked about genetics in high school and growing up, (we were experiments to other people), I was forced to look some of this stuff up. That's when I came across chimera's. This show on Discovery showed a baby boy/girl that was half black/ and half white. On her white side she was a woman (ovaries and all) but on his black side, he was a male. There was literally a line down the center of him where the skin color switched. Some people have asked me if that means my sister and I could have become chimera's if we had re-joined. Not possible. WE ONLY HAVE ONE SET OF DNA. THE SAME DNA. There must be 2 sets of DNA, from fraternal twins, that combines in the womb. NOT 1 egg that splits and re-joins, but 2 eggs that start apart and join together at some point in the womb. Other mother's have been accused of having kid's that weren't theirs, even when the birth was witnessed. Even though their are only 40 or so documented cases of Chimera's in the United States. there are likely to be a few more. So when a child that was not produced by in vitro fertilization, is genetically not the mother's, how come no one thinks of this? On the Discovery health show....they did not test the mother, and they thought for about 3 years the kid's were not hers. They finally believed the mother, father, family, and friends, when another baby was witnessed born to that mother (by the state) and the DNA was "incorrect". Chimera is the first thing I would have tested for. It's the only possible explanation. When the father is the father, but the mother isn't, and you saw her give birth, isn't that what you would think?


bakerplace
Posted 18 November 2007 at 09:19 am

clayton said: "I saw a segment about this on Discovery about 6 months ago. Same story, different women. They showed some of the different scientific evidence the scientists had. One characteristic of human chimeras was that there bodies were covered in checker-board patterns all over their bodies. I can't seem to find any pictures of human chimeras but here is a picture of a chimera orange[fruit].

http://zimmer.csufresno.edu/~earlb/chimera.htm"

what is the name of the program that was on the discovery channel? I am a chimera I have the marks on my stomach. (my story) When my mom was pregnant w/me she was frighten by a lizzard. she screamed! her mother asked if she had grabbed her face she said no she grabbed her stomach. her mother said the baby would be marked there. I guess she was right, because I am. twins do run in my family. I have always felt that i should have been a boy. when i saw the show on discovery i knew they were talking about me and i knew my brother name would start with a (D.) I was thinking damond or darren, so i called my mom and asked what my name would have been if i had been a boy... she said "Dion" is that wierd or what? Now i'm wondering how to get me and my two children tested. but I'm not a rich woman. I've called a few tv shows but they aren't interested. but my family tkinks I'm crazy so I would like to show them the tv program i saw on discovery. Please help me find it. this is my email address bakerplacedeer@netzero.net Thanks, "D"


becca inspired
Posted 17 February 2008 at 05:03 pm

I am so thankful for watch the Discovery Health show about chimera, and then finding this article about the disorder. I am only seventeen years old but I have always known that I wanted to be a researcher in the medical field when I get older and go to college, but now I know exactly what I want to research/study, chimera. Thank you!


Mejan
Posted 24 February 2008 at 10:42 pm

I agree with curiouser&curiouser, and I am also wondering if I am a chimera. I was born male, but I was told I had a twin sister that died before we were born. It is the stuff of "The Missing Twin" syndrome.

I have known since before birth that I was a woman, but was born in a male body. It is a secret I have hidden for 49 years now, but finally I am doing something about it. I have been on hormone therapy for just over 2 years, and have noticed something unusual. All sources tell me that starting at such a late age, I would be lucky to get a "AA" to "A" cup, but they are "B" and still growing. My Doctor tells me that they are at the same stage as a young girl would have 2 years after puberty. If they go all the way to "C" or larger, it will break the records for such a late starter.

By the way, the term is Transgender if you have Gender Dysphoria, which is the feeling or belief that your inner self (Ego, Id, "Self") is opposite to your physical and /or genetic gender. Transsexual is if you actually start making physical changes to your body to become the other gender, and learning mannerisms, habits and start dressing like that other gender.


Jonny
Posted 06 March 2008 at 12:57 am

indra c said: "So does this make David Bowie a human Chimera?"

David Bowie's eyes aren't actually different coloured, it just looks that way because one of his pupil's is permanently dilated from being punched in the eye with a ring.

Unless of course Wikipedia is wrong...


wishes to be unknown
Posted 01 May 2008 at 11:43 am

hi all i am a chimera i look and sound male and that is what my birth certificate says but in addition to all of the male parts i was also born with fully formed and functional female reproductive organs.
an experiment that was done using one of my eggs and my own sperm proved i could impregnate my self but i have no vagina or labia so it would need to be done surgically .
f.y.i. i would really rather not know it has been 20 years of hell always fearing you will be found out then labled a freak and most people would .
please just leave us alone !


BenKinsey
Posted 12 September 2008 at 08:15 am

ref said: "I had to become a part of this discussion because I also saw the Discovery Channel show and got a huge shock when they showed the image of the body with two different pigmentations, divided in the middle, I have the same thing! My torso is almost exactly divided down the middle from my upper chest to my waist and around under my arm and on my back, also exactly to the center. I have always thought it was a big birthmark and I was initially freaked out to think that I was two people in one!
Then I started thinking about how when I was a kid and our whole family was together, I often had a feeling that someone was missing. . .I'm not joking.
Anyone else know of someone with a half and half body?"

That is insane(its amazing to think about not that you are crazy)! It's as if your mind was aware of your neverborn twin. Makes you wonder about the mental and emotional connections that twins have. I've heard about twins sensing that the other, though far away, was in danger and it turns out that the feeling was warranted. And that this all went down in real time. I don't know what to think about it all but DI. I would love for research to be done regarding transgender feelings and chimeras. If that is the case then chimeras aren't as rare as once thought and shouldn't feel so self-conscious right?


kimberlyfarraj
Posted 13 December 2008 at 04:49 pm

I don't know if it's how they ruled out baby switched but I watched a show on this woman and another woman like her and i do know they tested Jane's family (mother, father ect) and Janes children matched her familys DNA so they knew that they were related.


billylogan
Posted 05 January 2009 at 10:37 am

At first I thought in chimeras would be mixed cells with two diferent DNA's but at cell level. But I see that in a person suffering from chimera one half (can be one third? or upper and lower?) is different from the other half. But then not only the color skin would change but also the leg, arm... size. And what about the internal organs or brain? And why should merge two parts with different DNA.

It seems for me too complicated to succeed. Is more easy in twins when the first group of cells divide into two parts. People has a lot of imagination... The only way for chimeras would be at the cell level like two cell colonies sharing the same space and mixed.

About the two XX chromosomes in women I suppose that the specific X chromosome expressed is completely random and also at a cell level. So it would not be visible at a superior level. People allways prefer original lies to boring thruts. I didn't want to spoil your show ;-)


oddeyeami
Posted 18 February 2009 at 12:33 pm

how would you even try to find out if you are a chimera? I am a mother of 1 . I have had heterochromia since birth as well as super-numery nipples. could i be on to something? I am the only one in my family that dont 2 brown eyes and the only 1 with 2 identical extra nipples(they never developed). Is this a common thing in chimera ? any info be helpful. thanks.


Gizmo
Posted 19 February 2009 at 05:43 pm

Hi, I have recently discovered that I am also a chimera and would love to see the Discovery Channel Shows mentioned above - if anyone knows where thay can be found, please post details.
Like a few people have mentioned, I think I was aware of the possibility of being chimera before it was even confirmed but hindsight is a wonderful thing. I also have some of the more obvious signs, different coloured eyes, straight thumb and a hitchikers thumb, different hair growth patterns and when younger had a definitive streak of blonde hair that people assumed was dyed. Another interesting pointer was that when I became a blood donor I was registered as a different blood group than that listed when I was born. I find it pretty amazing that something like this which I'm sure would interest a lot of people, has so little information about it online. If anyone has any good reference site details, I'd genuinely appreciate details.
oddeyeami #57 - re: the extra nipples, from what limited info that I have been able to find, it is not mentioned as a chimera trait but, and it's a big but - when you read any of the blogs or visit any forum where this is a topic, there is a very high percentage of people who have extra nipples that display other chimera traits, some of whom are also confirmed by DNA sampling as chimera.
Just another quick observation, given the comments on this site and numerous others , it would appear to be a subject that psychologists would benefit from studying, not just from the point of gender assignment but also for a myriad of other studies.


oddeyeami
Posted 19 February 2009 at 06:36 pm

thanks for your imput Gizmo, look forward to hearing more in this interesting topic. Jennifer.


aster
Posted 24 September 2009 at 10:01 pm

I think I am a star child Chimera; I don't need to have sex to have children; my DNA is beemed to me from a star system; after reading up on the Chimera phenomenon, I think I am a chimera; I have two different irises; my doppelganger said I have a twin who died and I absorbed her; I always felt I was a twin; I don't look any different but deep down inside I know I am a chimera. I haven't blood tested but I seem to be ageless; and I should have died many times but everytime I keep surviving so I think when I died my chimerism takes over or something. It will be interesting to see how my DNA matches my children. I have over 300 daughters and I am not sure how many sons I have. Still trying to determine that


deenie1029
Posted 28 July 2012 at 08:26 pm

I think I am chimera. I was born with 2 different conflicting bloodtypes, and needed transfused after birth. My eyes change colors, they don't always match. I would like more information if you please.


Dylan badcock
Posted 13 February 2014 at 03:08 pm

Awesome but need more info like when was it found and who found it otherwise it is pretty interesting


Dylan badcock
Posted 13 February 2014 at 03:10 pm

aster said: "I think I am a star child Chimera; I don't need to have sex to have children; my DNA is beemed to me from a star system; after reading up on the Chimera phenomenon, I think I am a chimera; I have two different irises; my doppelganger said I have a twin who died and I absorbed her; I always felt I was a twin; I don't look any different but deep down inside I know I am a chimera. I haven't blood tested but I seem to be ageless; and I should have died many times but everytime I keep surviving so I think when I died my chimerism takes over or something. It will be interesting to see how my DNA matches my children. I have over 300 daughters and I am not sure how many sons I have. Still trying to determine that"

???


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