Chimera’s are people that have two distinct sets of DNA and are usually a result of the person absorbing an unborn twin early in gestation. In the vast majority of cases, this little twist will remain unnoticed due to the fact that only a handful of organs are affected by the change which allows the trait to remain unnoticed. However, a U.S. man was one of the few who would notice when he discovered that he is not the father of his newborn infant but rather it’s “uncle.” In this case, his sperm carried the DNA of his absorbed twin which, on a genetic level, made the man not the father. This is the first reported instance of sperm containing the twin’s DNA although a women recently had a similar situation when her ovaries contained the DNA of her twin. The baby is reportedly in good health and should suffer no complications going into the future.
See Shehab Kahn, ‘Human chimera’: Man fails paternity test because genes in his saliva are different to those in sperm, Independent, October 26, 2015.
Special thanks to Riley Branch for bringing this article to my attention.
