Man donated his sperm with cancer-causing gene to conceive over 200 children; Here's what happened next

A man donated his sperm without knowing that it had cancer-causing gene present in it (Picture Credit: Pexels)

A man who donated his sperm has fathered over 197 children across Europe. However, as per the findings of an investigation, the man had unwittingly harboured a genetic mutation that increases the risk of cancer in the children who have inherited this mutation.

Among the children that the man has fathered, some have already died and only a minority of them who will inherit the mutation have the chance to escape cancer in their lifetime.

The investigation has been conducted by 14 public service broadcasters, including the BBC, as part of the European Broadcasting Union's Investigative Journalism Network.

The sperm was not sold to UK clinics. BBC said that there is a "very small" number of British families who used the donor's sperm while undergoing fertility treatment in Denmark. The families have been informed about the finding of the investigation.

It was Denmark's European Sperm Bank that sold the sperm and it confirmed that the sperm was used to make too many babies in some countries.

About the donor

The anonymous man who donated his sperm was paid and he started doing so when he was a student in 2005. At the time of donating the sperm, the man had passed the donor screening checks. However, the DNA in some of his cells mutated before he was born. It damaged the TP53 gene that has a crucial role to play in preventing body's cells from turning cancerous.

Most of the donor's body doesn't contain the dangerous form of TP53, but about 20% of his sperm does. Therefore, any children made from affected sperm will have the mutation in every cell of their body.

The European Sperm Bank said the "donor himself and his family members are not ill" and such a mutation is "not detected preventatively by genetic screening". After the finding of the investigation was revealed, the sperm bank said they "immediately blocked" the donor once the problem with his sperm was discovered.

His sperm was used by 67 fertility clinics in 14 countries. The BBC is choosing not to release the donor's identification number because he donated in good faith and the known cases in the UK have been contacted.

This whole thing is called Li Fraumeni syndrome and it leads to up to 90% chance of developing cancer, particularly during childhood. It also leads to an increased risk of developing breast cancer in later stages of life.

"It is a dreadful diagnosis," Prof Clare Turnbull, a cancer geneticist at the Institute of Cancer Research in London, told the BBC. "It's a very challenging diagnosis to land on a family, there is a lifelong burden of living with that risk, it's clearly devastating."

Children who have died

Doctors reported they had found 23 with the variant out of the 67 children known at the time. 10 of them had already been diagnosed with cancer. So, far, it is unknown how many of the children that the donor has fathered over the years have inherited the dangerous variant.

Cancer geneticist at Rouen University Hospital Dr Edwige Kasper in France shared, "We have many children that have already developed a cancer. Some of them have developed already two different cancers and some of them have already died at a very early age."