You Could Be Your Own Twin
Tetragametic chimerism is also called vanishing twin syndrome, and it occurs when a twin dies in utero, usually early in a pregnancy. The remaining twin then absorbs its sibling's fetal tissue, resulting in a baby with two genetic signatures. The consequences of this condition can seem quite strange, especially in a world where we rely on the accuracy of DNA testing. One tetragametic chimera was determined not to be the mother of a child she had definitely given birth to-after she failed a maternity test, the "real" mother was revealed to be her unborn twin, whose DNA resided in her body!
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Key Facts In This Video
A chimera is someone with multiple sets of DNA. (0:28)
It's estimated that about 1 in 8 single childbirths actually starts as a multiple pregnancy. (1:51)
Chimerism makes it possible for someone to give birth to a child, then fail a genetic maternity test related to that child. (2:06)