We’ve all seen paternity tests on TV, the heated anticipation as the host reveals “You’re not the father!” So when a case study recently surfaced about a man who failed a paternity test no one understood why it mattered so much. It ends up that the father is the man’s twin brother… who he absorbed in the womb. And that’s where this story gets good.
A couple in the USA struggling to conceive their second child used intrauterine insemination at a fertility clinic. This procedure involves placing washed, concentrated sperm in the uterus around the time of ovulation to increase the number of strong sperm reaching the fallopian tubes. The procedure was successful and the couple conceived a healthy baby boy.
However, a routine medical test shortly after the baby was born revealed that his blood type didn’t match his parents. The baby was born with AB while both of his parents had A. While there are rare cases where children of AB parents are born with A or B only, the children generally have AB blood.
The only logical conclusion was that the father’s sperm must have been mixed up with someone else’s at the fertility clinic, which would have been devastating news. The father took a paternity test that confirmed, as feared, he was not the father. But the clinic denied any mixup, saying that there had only been one other couple conceiving at the time and there was no paternity issues with their case. So where did this sperm come from?
On a hunch the couple’s lawyer recommended that the father take another paternity test, this time with two samples of DNA: one from his cheek and one from his sperm. The results revealed two different strands of DNA. The father is a human chimera.
A chimera a single organism consisting of distinct genetic makeup. In humans it can results in multiple different sex organs or two blood types. As a result of the obvious legal issues, such as those of this couple, there are strict ethic codes to forbid experimentation of human cells in this way. But sometime’s nature has its own agenda and naturally occurring chimeras pop up from time to time.
The baby’s DNA matched the DNA of the father’s sperm, which they found to be almost identical to the father’s cheek DNA. It ends up that he absorbed a twin in the womb and in doing so also absorbed his DNA. The father is still technically the both the legal and biological father of the baby: both DNA strands are in his body, regardless of the fact that one previously belonged to the twin. He is his son’s father… and uncle.