The human nature never surprises us. A man took a paternity test on the newborn child of and the Results showed that the actual DNA in his sperm did not come from him, but from the unborn twin brother that had been absorbed into their mother's womb.
No, this is not a strange novel of science fiction. It is a rare but not-unknown medical event called chimerism (chimerism).
While many pregnancies start with multiple embryos, often all but one, they are eliminated. But sometimes DNA from the lost brothers is absorbed by the surviving fetus, leaving parts of DNA to the survivor. About one in eight pregnancies implies such a case, although most go unnoticed until a genetic test is done.
The chimera was discovered when the parents requested a clinical fertility test because their newborn son had a different type bloodof his parents. Concerned that the clinic had used the wrong sperm after the first paternity test failed, the clinic told them that, in fact, he was the only white donor on that day, and that their son is Caucasian like them. The next genetic test from the service 23andMe showed a strange result: the son and father were genetically linked, but his father was genetically his uncle !!!.
Further tests showed that at least the 10 percent of the father's sperm came from absorbing his brother. According to BuzzFeedNews, this is not unheard of, although usually in women they fail in the maternity test.
