'Human chimera': Man fails paternity test because genes in his saliva are different to those in sperm
It is thought cells from a miscarried sibling were absorbed by the man while he was in the womb
Your support helps us to tell the story
From reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. Whether it's investigating the financials of Elon Musk's pro-Trump PAC or producing our latest documentary, 'The A Word', which shines a light on the American women fighting for reproductive rights, we know how important it is to parse out the facts from the messaging.
At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.
The Independent is trusted by Americans across the entire political spectrum. And unlike many other quality news outlets, we choose not to lock Americans out of our reporting and analysis with paywalls. We believe quality journalism should be available to everyone, paid for by those who can afford it.
Your support makes all the difference.A US man has failed a paternity test after doctors revealed his dead twin, whose DNA the man absorbed in the womb, is the genetic father of the child.
The 34-year-old man is the first ever reported case of a paternity test being fooled by a human chimera, someone with extra genes absorbed from a twin lost in early pregnancy.
Approximately one in eight single childbirths are thought to start as multiple pregnancies and occasionally cells from the miscarried siblings are sometimes absorbed in the womb by a surviving twin.
According to Buzzfeed, the Washington couple took a paternity test after their son’s blood type didn’t match that of either parent. After having a child with the help of fertility clinic procedures, they feared that sperm donors may have potentially been mixed up.
After the initial failed fertility test, they took a genetic ancestry test which suggested that the man was actually his son’s uncle.
The father’s sperm was found to have 10 per cent of a genetic match to the infant. The genes in his sperm were different to that in his saliva and it has been concluded that the father of the boy is effectively the man’s own unborn twin.
There have been chimera cases in the past. Karen Keegan from Boston found that her blood cells had one set of genes and her ovaries held distinctly different ones. Those ovaries had produced the eggs that led to two of Keegan’s sons holding genes different from her own.
The true genetic mother was a twin sister that she never knew and who was never born.
Searches for chimeras are incredibly complicated as the genes only feature in detectable amounts in very few organs. As more people turn to fertility clinics to help them have children, chimerism may become more common, as fertility treatments are more likely to lead to multiple births.
Subscribe to Independent Premium to bookmark this article
Want to bookmark your favourite articles and stories to read or reference later? Start your Independent Premium subscription today.
Join our commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies
Comments