A major investigation has revealed that a sperm donor carrying a dangerous genetic mutation has fathered at least 197 children across Europe, leading to multiple cancer diagnoses and several deaths among the affected offspring.
The anonymous donor, who began donating in Denmark in 2005, unknowingly carried a mutation in the TP53 gene a critical gene that helps prevent cells from becoming cancerous.
Up to 20% of his sperm contained the mutation, even though he remains healthy himself.
Children conceived from affected sperm inherited the mutation in every cell, resulting in Li-Fraumeni syndrome, a rare disorder that gives carriers up to a 90% lifetime risk of developing cancer, often beginning in childhood.
Children Already Diagnosed, Some Dead
Doctors raised concerns earlier this year after noticing a pattern of cancer cases among children conceived via the same donor. Of 67 children initially identified, 23 carried the variant, and 10 had already developed cancer, according to French cancer geneticist Dr Edwige Kasper.
Some children have suffered multiple cancers; others have died.
The European Broadcasting Union’s Investigative Journalism Network, including the BBC, has now confirmed that at least 197 children were born using the donor’s sperm across 14 countries and 67 fertility clinics. The total number could be higher, as not all countries have provided data.
UK Families Also Affected
Although the sperm was not sold directly to UK clinics, the UK’s fertility regulator says a “very small number” of British women travelled abroad mainly to Denmark for treatment using the donor’s sperm. Those women have been contacted.
Sperm Bank Admits Excessive Use
Denmark’s European Sperm Bank, which distributed the sperm, expressed sympathy to affected families, acknowledging that the donor’s sperm was used beyond legal limits in some countries.
For example, Belgium allows sperm from one donor to be used by only six families, but the donor fathered 53 children there alone.
The bank said the mutation could not have been detected through routine donor screening.
Experts say the case highlights gaps in global sperm-donation regulations.
There is no international law limiting how often donor sperm can be used, even as donor sperm is distributed globally.
Prof Allan Pacey, former head of the Sheffield Sperm Bank, said dependency on large international sperm banks increases risks:
“You can’t screen for everything… If we make screening any stricter, we may end up with no donors at all.”
The case follows another involving a man who fathered 550 children, intensifying calls for stronger limits.
The European Society of Human Reproduction and Embryology has proposed capping donors at 50 families, though this would not prevent rare genetic issues.
Families Face Lifelong Uncertainty
Parents like Céline (not her real name), whose daughter carries the mutation, say they now face a future overshadowed by cancer risks.
“We don’t know when, we don’t know which one… but when it comes, we’ll fight,” she said.
BBC.