The Daily Populous Sunday December 14th, 2025 morning edition
Authored by scienceclock.com and submitted by iron-button

A Danish sperm donor carrying a rare genetic mutation linked to a very high risk of cancer has fathered at least 197 children across Europe, according to an investigation reported by Denmark’s public broadcaster DR.

The donor, known by the alias “Kjeld”, unknowingly carried a mutation in the TP53 gene, which is associated with Li-Fraumeni syndrome. The condition can raise a person’s lifetime cancer risk to as much as 90 percent. The donor himself is healthy and unaware of the mutation, which is present only in some of his sperm cells, according to BBC News.

The sperm was distributed by European Sperm Bank (ESB), one of the largest in the world, and used between 2006 and 2022. DR’s investigation found that the donor’s sperm was supplied to 67 fertility clinics in 14 European countries, resulting in 99 children born in Denmark alone.

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The genetic defect was identified after children conceived using the donor’s sperm were diagnosed with cancer and found to carry the same mutation. Once confirmed, the sperm bank blocked further use of the donor’s samples.

In a statement cited by the BBC, European Sperm Bank said the mutation is “not detected preventatively by genetic screening” and added that it “immediately blocked the donor once the problem with his sperm was discovered.”

Medical experts warn that while most of the donor’s body does not contain the dangerous form of TP53, up to 20 percent of his sperm carries the mutation. Any child conceived from those sperm will have the mutation in every cell of their body. Some children linked to the donor have already developed cancer, and several have died.

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“We have many children that have already developed a cancer,” said Dr Edwige Kasper, a cancer geneticist at Rouen University Hospital in France, quoted by the BBC News. “We have some children who have developed already two different cancers, and some of them have already died at a very early age.”

The case has raised renewed concerns about the lack of a unified European limit on how many children can be conceived from a single donor.

“I am shocked by the scale of the sales,” said Kent Kristensen, associate professor of health law at Aalborg University. “And it also shows a structural breakdown in the way the reporting system should work, because it hasn’t worked.”

PeriwinkleWonder on December 13rd, 2025 at 13:23 UTC »

I will never understand this. Sperm is cheap and widely available!

filtersweep on December 13rd, 2025 at 09:23 UTC »

I am adopted- took one of those My Heritage DNA test- boom! There is my birth mother and all my half siblings

lego_not_legos on December 13rd, 2025 at 06:54 UTC »

It seems ridiculous for any sperm bank to be using the same donor for more than a few kids. Are there really so few?