A major European investigation involving 14 media organisations has uncovered that an anonymous sperm donor, unknowingly carrying a genetic mutation that dramatically increases cancer risk, has fathered at least 196 children across Europe.
According to the BBC, which participated in the investigation, some of these children have already died, and only a small number of those who inherited the mutation may avoid developing cancer during their lifetime.
The Danish European Sperm Bank, which sold the sperm, expressed its “deep sympathy” to the affected families and admitted that the donor’s sperm was used to conceive an unusually high number of children in several countries, including Greece, as shown on a BBC map.
The sperm came from an anonymous donor who began donating in 2005 while a student, and continued for approximately 17 years. Although he had passed standard donor screening, some of his DNA had mutated before birth.
“This caused damage to the TP53 gene, which plays a critical role in preventing cells from turning cancerous. Most of the donor’s body does not carry the dangerous form of TP53, but up to 20% of his sperm does. Children conceived from the affected sperm will have the mutation in every cell of their body. This condition, known as Li-Fraumeni syndrome, carries up to a 90% lifetime risk of cancer, particularly in childhood, as well as breast cancer later in life,” the BBC report explains.
“It is a devastating diagnosis. It’s very challenging for a family, with a lifelong burden of living with this risk,” commented Clare Turnbull, a cancer geneticist at the London Institute of Cancer Research.
The European Sperm Bank emphasized that the donor and his family are healthy and that such a mutation “cannot be detected proactively through genetic testing,” adding that the donor was immediately excluded once the issue was discovered.
Children have already died
The case came to light when doctors examining children with cancer linked to donor sperm raised concerns with the European Society of Human Genetics. At the time, they identified 23 children with the mutation out of 67 known cases, ten of whom had already been diagnosed with cancer.
“The investigation revealed that the total number is at least 197 children, though this may not be final as not all countries have submitted data. It is also unclear how many of these children inherited the dangerous variant,” the BBC reported.
“We have many children who have already developed cancer. Some have even developed two different types of cancer, and a few have already died at a very young age,” said Edwin Kasper, a cancer geneticist at Rouen University Hospital, who presented the initial findings.