What sounds extremely wrong, but is actually correct?

What if I told you that you might've had a fraternal twin but you ate it?

This might sound like some horror story or fiction but it isn't. It's a medical phenomenon called “chimera”.

In 2002, a pregnant American woman was fighting with her ex over the custody of their 2 children. And as the procedures of that case required, both of them provided DNA samples to prove that they are the biological parents. However, the result of the tests proved that her ex is indeed the father…. But she's not the mother !

All papers and witnesses proved that she's the mother no doubt but her DNA said otherwise. She was accused of being a fraud. However, the judge decided that the case will be on hold until the 3rd child is born and tested. And when the child arrived, once again the DNA of the mother did not match [1] ! After taking many samples from her body, the only DNA that actually proved that she's the mother was a sample from her uterus.


After research doctors discovered that the mother simply had the DNA of two people in her body. She had a fraternal twin in the womb. But when the embryo died early on, she absorbed its cells, which is the “chimera” phenomenon.

There are other cases where the phenomenon was discovered. A Dutch athlete woman was forced to retire and not participate in any races in 1950. The reason was because even though her papers and her claims indicate that she's a female, her DNA has traces of chromosome Y, meaning it reveals she is a male ! Because medicine was not advanced enough in her time, it took years for them to discover that she just has the DNA of two people inside her[2].

In another case, a man's body (blood type O) rejected the bags of blood transferred to it despite being blood type O as well… supposedly. After research, turns out that the donor had a fraternal twin, an actual alive one this time. And both of them had a mixture of 95% blood type O and 5% blood type B. Meaning both of them absorbed a third fetus when they were in the womb.[3]

Some researches believe that chimera could be responsible for:-

eyes differing in colour, patchwork skin coloration, and ambiguous external genitalia, which is a sign of hermaphroditism (having both male and female reproductive organs).[4]

Some also believe that it could be the cause of some auto-immune diseases as the body senses the presence of foreign cells and keeps attacking them.

The phenomenon is more common than we think. Some suggest that 1/3 of people are chimeras. But most of us go about our lives without ever knowing it. Sometimes the foreign cells are too little that they don't affect us medically.

There is still a lot to be discovered when it comes to this phenomenon but it opens the door to many questions.