Sperm Donor with Cancer-Causing Mutation Fathered Nearly 200 Children

A recent investigation has revealed that a sperm donor who unknowingly carried a genetic mutation that increases the risk of cancer, has fathered at least 197 children across Europe. Some of these children have already died and most of them are likely to eventually develop cancer. This investigation was conducted by 14 public service broadcasters, including the BBC, as part of the European Broadcasting Union's Investigative Journalism Network.

The sperm was sold by the European Sperm Bank (ESB) in Denmark. The company said that the "donor himself and his family members are not ill" and that such a mutation was "not detected preventatively by genetic screening".

ESB was first alerted in April 2020 that a child conceived from one of their sperm donors had a genetic mutation. The donor’s sperm was tested but no genetic mutation was found. Later on in 2023, ESB was alerted to at least another child conceived from the same sperm donor with a mutation that developed cancer. ESB went on to test several samples and found that the donor’s sperm carried the mutated gene.

Upon this discovery, the European Sperm Bank “immediately blocked” the use of the donor’s sperm. The company also apologized, expressing their “deepest sympathy” to the families affected. However, the sperm had already been overused in many countries, having been supplied to 67 clinics in 14 different countries.

The donor had been paid to donate his sperm since 2005 and the donations had been used by many women for around 17 years. The donor himself is healthy and passed screening checks which allowed him to donate his sperm. However, the DNA in his cells had actually mutated before he was born, causing damage to a gene called TP53.

The TP53 gene is a tumor suppressor gene which prevents the body’s cells from turning cancerous. While most of the cells in the donor’s body do not contain the mutated form of the gene, it was found that approximately 20% of his sperm did. When the mutated sperm is used in in-vitro fertilization (IVF), this mutation will end up in every cell of the child’s body. This is known as Li Fraumeni syndrome and it causes the child to have up to 90% chance of developing cancer.

For those affected, MRI scans and abdominal ultrasounds are required every year to monitor for the growth of tumors. Additionally, affected women may also choose to remove their breasts to further lower the risk of developing cancer.

While the exact number of children that have inherited the genetic mutation is unclear, it is estimated that at least 197 children are affected. However, this number is not final as data has not been obtained from all countries.

Dr Edwige Kasper, a cancer geneticist at Rouen University Hospital, in France, presented the initial data at the annual conference of the European Society of Human Genetics in May. She shared, "We have many children that have already developed a cancer. We have some children that have developed already [sic] two different cancers and some of them have already died at a very early age."

She also added that an initial 67 children were identified to be born from the sperm of this donor. Out of which, 23 of them are found to have the mutated gene. Additionally, 10 of these 23 children have been diagnosed with cancer. While there is a high risk of these children developing cancer during their lifetime, there is also a chance of them transmitting the mutated gene onto their own children.

Such genetic factors can significantly increase an individual’s risk of developing cancer. Hence, early screening and genetic testing is crucial for those at higher risk, to enable timely prevention and treatment.