The phenomenon behind Chimerism - Do you know that DNA test can lie while being true ?

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It's a pleasure to be here again with this interesting topic, I Know many of you would love it.
I was looking for a good topic that would actually summarize the context of this article, so from that search gave rise to the sub objective of this test ("Did you know that paternity test can lie while being true"), which we would also look into.

I believe many of you must have come across this topic "Chimerism" or have heard about the word "Chimera".
I got to know about it from an argument in our group about a paternity case, where the DNA profile of the biological father to a child did not proof the paternity...
I asked a question, "how is it possible ?" that then lead me to a new knowledge about Chimerism.

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*What's is Chimerism ?

Chimerism is a rare congenital condition involving one person having two different sets of DNA.

A chimera is a single organism that is made up of cells from two or more individuals.

There are lots of aberration(abnormal change) in the Chromosomes that have been scientifically proven to exist, but it occurs in rare cases and that’s probably why alot of people haven’t heard about it.
That we haven’t heard about it doesn’t make it a myth still. Let me throw more light on the genetic condition.

Is it possible for one person to have two different sets of DNA ?
Yes!! It’s very possible and here’s how it happens...

• It can happen when a woman is pregnant with fraternal twins and one embryo dies during the early stage of the pregnancy and the other embryo absorbs it’s twins cells.

A Californian singer named Taylor Muhl has identified her self to be a Chimera, from her documentaries she has a twin chimerism,
[credit:

jimjordaphotography published in a public space by taylor muhl herself

taylormuhl_This was the first photo released publicly displaying my physical trait, which is caused by a rare genetic condition I was born with called, Chimerism.
If you’re new to my page, I was born with a genetic condition called chimerism, which makes me “My Own Fraternal Twin.” I have two sets of genetics, blood and immune cells. The second color pigmentation on my torso is my twin sisters’ genetic makeup.
My particular case of Chimerism causes autoimmune disease. My two sets of genetics clash, which then lowers my immune system and causes it to work overtime. I went undiagnosed more than half my life due to my conditions rarity (only 100 cases documented in the world)
I want to prevent that for others, so I started spreading Chimerism awareness, it’s link to autoimmune disease and I became a body positivity model to help inspire others with physical differences like myself_taylormuhl

• It happens during normal pregnancy when the embryo absorbs some of it’s mother’s cells.

• It can also happen after a bone marrow transplant (cases of sickle cell anaemia and leukemia).
The treatment of leukemia involves chemotherapy, which is used on the patients to destroy the cancer cells.
In bone marrow transplant also,
Chemotherapy or radiation is used to destroy all the recipient’s diseased bone marrow, which is been replaced with a healthy marrow from a donor.
Note that: a recipient is one who receives or collects.
a donor is one who gives or donates.
Because marrows are regenerative in nature, the donor’s bone marrow will regenerate and continue producing blood cells with complete set of the donors DNA copies, this adjusts the recipients body cells making it to have cells and DNA of two different human being. In this case the patient becomes an artificial Chimera. (artificial Chimerism)

In the case where there's complete change in the DNA of the recipient after bone marrow transplant, the recipient becomes a complete Chimera, the reverse maybe the incomplete Chimerism where the DNA change after bone marrow transplant is partially, the recipient becomes a partial Chimera.

This type of chimera has inspired one some interesting storylines in pop culture, Motherboard reports. The 2015 film "Bad Blood" is all about a cancer-patient-turned-serial-killer using the DNA in his blood to implicate his bone marrow donor.source

• A woman named karen keegan has also had a case of false negative DNA test, when the tests said that she wasn’t the biological mother of her children,

In Boston Karen Keegan had received a chilling phone call from her doctor. It came during a very difficult time in her life, just as she needed a kidney transplant.
Keegan recalled what the doctor said to her: "Mrs. Keegan, we have some unusual news to report to you. We've never had this happen before, but your children don't match your DNA."
That revelation came after her family members had had their blood tested for compatibility.
"Any child from a mom and dad should inherit genes from both the mom and the dad. In Keegan's case, it appeared that her two boys hadn't inherited any of her DNA," said Dr. Lynne Uhl, a pathologist and doctor of transfusion medicine at Beth Israel Deaconess Medical Center in Boston.source

But it turned out that the DNA in her blood was different from the DNA in her ovaries.
Doctors said that the extra DNA probably came from a dead fraternal twin.

Some the issues that is usually associated human Chimera includes;
• Hyper/hypo pigmentation of the skin - difference in skin coloration
• Autoimmune diseases
• Genital/sexual problems
• psychological issues like depression and stigmatization etc

Do you know that paternity test can lie while being true ?

There has been many recorded case of failed paternity test which was brought about by the case of Chimera father, like the case of the made who has a different DNA in the silver (buccal cavity) and different DNA in the sperm cells.

A US man has failed a paternity test after doctors revealed his dead twin, whose DNA the man absorbed in the womb, is the genetic father of the child.
The 34-year-old man is the first ever reported case of a paternity test being fooled by a human chimera, someone with extra genes absorbed from a twin lost in early pregnancy.source

So from the above, the story told that basically, the father of the child is actually the biological uncle, while the dead twins brother whose cells was absorbed during pregnancy is actually the biological father to the baby, So crazy right, lols.

In this case, in real essence the man is the father, but because he's a Chimera, he contains a double DNA, so in this vein, it shows that his sperms cells contains most or completely the absorbed cells of the dead twins brother.
Therefore genetically, he's not the the father but the uncle, because the DNA profile doesn't matter with baby, rather about 10% match from the DNA test of the man suggest that he's the uncle to the baby. (As the story told)

The case of Chimerism has constituted a pitfalls to forensic science, thereby making it more difficult for forensic scientists to draw their conclusion in the scene of crime and paternity cases.

N.B; it is said that testing for chimerism is very difficult.
And many people live their whole life without being aware that they're human Chimera.

Thanks very much for your time, I appreciate!.

References
What's Chimerism

Taylor muhl story and advocate on awareness about Chimerism

She's Her Own Twin

'Human chimera': Man fails paternity test because genes in his saliva are different to those in sperm

It's possible for one person to have two different sets of DNA