Is it Possible for One Person to Have Two Sets of DNA?
It has been reported that some people have two different sets of DNA, and if they do, they are known as human chimeras.
Insider writes, in Greek mythology, a chimera was a fire-breathing creature with physical traits of a lion, goat, and dragon. However, human chimeras develop naturally, and some people aren’t even aware that they have doubles up on DNA.
You can end up as a human chimera in the following ways:
After a bone marrow transplant
During bone marrow transplants, doctors use chemotherapy or radiation to destroy all of the recipient’s diseased bone marrow, then a donor’s healthy marrow is put in its place.
The donor’s bone marrow will keep on producing blood cells that have the donor’s DNA, according to a Scientific American report. Therefore, the recipient becomes a chimera.
A paper in the journal Nature went on to explain that in “complete chimera,” 100% of the recipient’s blood cells have the donor’s DNA. But, the blood can also contain a mix of DNA from the donor, as well as the recipient. This is otherwise known as “mixed chimerism.”
When fraternal twins are in utero
Scientific American explains, when a mother is carrying fraternal twins, one of the embryos might die very early in the pregnancy. As a result, the other embryo can absorb some cells from the deceased one, causing it to end up with two sets of DNA.
During a normal pregnancy
Back in the 90’s, scientists discovered that a pregnant woman may retain some DNA from her baby, that’s if some fetal cells migrate outside the uterus. Scientifically this is known as “microchimerism.”
A simple way to prove this is to test the mothers of boys and see if they have any cells with Y chromosomes, which are only present in males. In one particular study, researchers sampled tissue from 26 women who had died during pregnancy or just after giving birth to a boy. In every sample, they found low concentrations of cells with Y chromosomes.
Similarly, a different study looked at the brains of mothers who had boys. They discovered traces of male DNA in 63% of the women, even in a woman who was 94 years old, Scientific American reported. This extended finding, suggests that microchimerism might continue to exist after pregnancy.