Student with cancer-causing genes fathers nearly 200 babies by sperm donation; some babies are already dead

A sperm donor, who carries a dangerous genetic mutation linked to a high risk of cancer, has fathered at least 197 children across Europe. A major investigation, involving the BBC, has found the alarming update.

Doctors treating donor-conceived children with cancer raised alarms at the European Society of Human Genetics. Then, the scale of the issue was determined.

The doctors identified 23 children with the mutation out of 67 known cases. Ten of them had already developed cancer. Further information was gathered through official requests and interviews. It showed that the number of children born from this donor was far higher, according to the BBC.

The final count may still rise. Data from several countries is still missing. It is unclear how many children carry the harmful mutation.

Who was the sperm donor?

The sperm donor was an anonymous student. He started donating in 2005 and continued for nearly 17 years. He was paid for his samples and initially passed all screening checks.

Doctors later discovered that a mutation had occurred in some of his cells before birth. This mutation damaged the TP53 gene, which normally protects the body from cancer.

Most of his body is healthy, but up to 20% of his sperm carry the faulty gene. Any child conceived from this affected sperm will have the mutation in every cell, which leads to Li Fraumeni syndrome.

This rare condition brings an extremely high risk of childhood cancer. It also carries a major risk of breast cancer later in life. Experts say the diagnosis is devastating for families as it creates a lifelong burden of medical checks and uncertainty.

The seller, Denmark's European Sperm Bank, has expressed their "deepest sympathy" for the affected families. It has also agreed that the sperm was used to make too many babies.

The donor is not ill, nor are his family members. However, he has now been blocked by the seller.

Children have already died

"We have some children that have developed already two different cancers and some of them have already died at a very early age," the BBC quoted Dr Edwige Kasper, a cancer geneticist in France, as telling the investigation:

A single mother in France conceived her daughter with the donor’s sperm 14 years ago. The young girl now carries the harmful genetic mutation.

The mother says her fertility clinic called her urgently and asked her to get her child tested. She does not blame the donor personally, yet feels it is unacceptable that she was given sperm that carried a serious risk.

The mother now lives with the constant fear of cancer affecting her daughter. She says they do not know when or what type of cancer may appear. However, they will fight it whenever it comes, even if it happens more than once.