10 children conceived with same sperm donor develop cancer and this leads to unfortunate discovery

10 children developed cancer, and this caused their families to begin asking questions that led them to make an unfortunate discovery

Some of their families traced the diagnoses back to a singular sperm donor with a rare genetic variant.

The situation began when two of the children’s families reached out to their respective fertility clinics after the kids were diagnosed with cancers linked to a rare genetic mutation, according to a new report from The Guardian.

The report was published on May 23, one day before Dr. Edwige Kasper, a French biologist, presented the case at the European Society of Human Genetics conference in Milan.

European Sperm Bank, which supplied the sperm, confirmed that the rare variant — which Kasper’s lab concluded was likely to cause Li-Fraumeni syndrome, an inherited predisposition to cancer — was found in some of the sperm, according to The Guardian.

It was soon discovered that more than two children were affected.

Separate but simultaneous investigations revealed that the variant, found in a gene called TP53, was present in a total of 23 of the children conceived with the donor sperm, 10 of whom had already been diagnosed with leukaemia, non-Hodgkin lymphoma and other cancers, the outlet reported.

Though 10 kids have been diagnosed thus far, the company also confirmed that the donor’s sperm was used to conceive many more children.

European Sperm Bank — which recruits sperm donors in Denmark, Germany and the Netherlands, according to its website — said that more than 67 kids were conceived using the donor’s sperm, and that all relevant fertility clinics were alerted to the situation.

A spokesperson for the company, Julie Paulli Budtz, told The Guardian the company is “deeply affected by this case.”

Budtz also said that, even with thorough testing prior to sperm donation, “it is scientifically simply not possible to detect disease-causing mutations in a person’s gene pool if you don’t know what you are looking for.”

Even if testing had unearthed the mutation, it was not yet linked to cancer in 2008 (the time of the donation) and would not have been detectable through standard screening procedures, The Guardian reported.

The outlet also said the donor is in good health and as a result, there was no reason to suspect the genetic mutation.
Dr. Edwige Kasper, a biologist at Rouen University Hospital in France, said it wasn’t even clear if the man’s sperm was used just 67 times or more.

“It’s a really good question that I’ve asked the sperm bank,” she said. “They didn’t want to tell me the denominator of the births for this donor.”

Dr. Kasper added: “We need to have a European limit on the number of births or families for a single donor.”

“We can’t do whole-genome sequencing for all sperm donors — I’m not arguing for that,” she continued. “But this is the abnormal dissemination of genetic disease. Not every man has 75 children across Europe.”