A Danish sperm donor whose samples were used to conceive nearly 200 children worldwide has been found to carry a rare genetic mutation associated with increased cancer risk, Denmark’s public broadcaster DR revealed Wednesday.
Between 2006 and 2022, the donor’s sperm was distributed to 67 clinics in 14 countries, resulting in at least 197 births, including 99 children in Denmark. The man, known by the alias “Kjeld,” was later discovered to be an asymptomatic carrier of a TP53 mutation, a rare genetic abnormality linked to cancer.
The European Sperm Bank (ESB), one of the largest in the world, was first alerted in April 2020 when a child conceived via the donor was diagnosed with cancer. Initial testing of the donor’s sperm did not detect the mutation, and sales resumed. However, in 2023, another case emerged, prompting further analysis that confirmed the donor carried the mutation in part of his sperm cells, though he remained unaffected himself. His sperm was permanently withdrawn from use in October 2023.
The Danish Patient Safety Authority confirmed that 99 children were born in Denmark through the donor’s samples, while 98 others were born abroad. ESB explained that the mutation was “rare and previously undescribed,” stressing that not all children conceived from the donor carry it.
The case has reignited debate over sperm donor regulations. While many European countries impose limits on the number of children per donor, no international rules exist to restrict cross-border use. At the end of 2022, ESB introduced a cap of 75 families per donor.
The company, which has facilitated more than 70,000 births globally over two decades, said the mutation could not have been detected by earlier screening methods, underscoring the challenges of genetic testing in fertility treatments.
