European man unaware he had a rare cancer-causing gene donated his sperm — 10 kids now have cancer

There are term limits — why not sperm limits?

The debate over how often a donor’s sperm should be used to conceive children has been reignited in Europe, after 67 children were birthed accidentally using the sperm of a man that had a rare cancer-causing mutation.

Ten of those 67 have been diagnosed with some form of cancer, The Guardian reported. More than 20 others are confirmed to have the variant.

The families of two of the 10 contacted their fertility clinics after their children developed cancers associated with the gene variant TP53.

The European Sperm Bank had supplied the sperm, and was able to confirm the TP53 variant was present in some of the unidentified donor’s sperm.

The mutation will typically cause the patient to develop Li-Fraumeni syndrome, an inherited predisposition to cancers like leukaemia and non-Hodgkin lymphoma.

The rare variant was not known to be linked to cancer at the time of the 2008 donation and would not have been detectable using standard screenings, the outlet reported.

At the moment, there is no agreement internationally on sperm and how often sperm from a single donor should be used. Recently, it was revealed a single donor was the father of 150 different kids.

“We need to have a European limit on the number of births or families for a single donor,” said Dr. Edwige Kasper, a biologist at Rouen University Hospital in France.

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

Added Kasper: “I analyzed the variant using population and patient databases, computer prediction tools and the results of functional trials and came to the conclusion that the variant was probably cancer-causing and that children born from this donor should receive genetic counselling.”

Children with the variant usually require monitoring via whole-body MRI scans as well as MRI scans of the brain and, as adults, the breast and abdomen.

Kasper said it wasn’t even clear if the man’s sperm was used just 67 times.

“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.”