A sweeping investigation by fourteen European media outlets has uncovered that a Danish sperm donor carrying a rare cancer-linked mutation has fathered close to 200 children across Europe. The case has raised urgent concerns about gaps in fertility-industry regulation and the limitations of existing genetic screening systems.
A Widespread Footprint Across the Continent
The donor, identified publicly only as Donor 7069 and known under the alias “Kjeld” began donating sperm in 2005 to the European Sperm Bank (ESB). At the time, he was a young student and passed all standard screening tests. Unknown to clinicians and regulators, however, a portion of his sperm carried a harmful mutation in the TP53 gene, which is associated with Li-Fraumeni syndrome, one of the most severe hereditary cancer disorders known.
His donations were eventually distributed to 67 fertility clinics in at least 14 countries, Journalists used freedom-of-information requests, interviews, and cross-border collaboration to identify at least 197 children conceived using his sperm – though experts believe the true number may be higher.
Authorities in the UK confirmed that a small number of British families who traveled abroad for treatment have been notified, even though the donor’s sperm was never supplied directly to UK clinics.
A Cancer-Causing Mutation With Life-Long Consequences
The mutation in the donor’s sperm affects around 20% of his reproductive cells, meaning he does not have Li-Fraumeni syndrome himself. But any child conceived from an affected sperm cell inherits the mutation in every cell of the body.
Li-Fraumeni syndrome dramatically elevates cancer risk:
- Individuals face up to a 90% chance of developing cancer by age 60.
- Around half develop cancer before age 40.
- Tumors may appear in childhood and can include bone cancers, brain tumors, adrenal cancers, Hodgkin lymphoma, and breast cancer.
French oncologist Dr. Edwige Kasper was the first to alert the medical community in May 2025. At that time, she identified 67 children linked to the donor, of whom 23 carried the mutation and 10 already had cancer. Several children have since developed multiple cancers, and some have died at very young ages.
Families are now undergoing intensive genetic counseling and surveillance. One French mother described the emotional toll of raising a child who could develop cancer at any time, calling it a constant fear of “not if, but when.”
Regulators Under Pressure After Major Oversight Failures
The case has drawn attention to longstanding concerns about the lack of cross-border oversight in donor conception. While most European countries cap the number of families a donor can help, those limits are not harmonized – and are easy to breach when sperm crosses national borders.
In Belgium, where a donor is limited to six families, sperm from Donor 7069 contributed to 53 children in 38 families, far above legal thresholds.
Experts say the root problem is the globalization of the fertility industry, which has created a marketplace where large sperm banks supply clinics in dozens of countries. This makes it difficult for regulators to track family numbers or enforce limits.Reproductive specialists, including Professor Mary Herbert, argue this case demonstrates the need for more comprehensive genetic testing of donors – as well as Europe-wide systems for tracking the use of donated sperm. Others warn that overly strict screening could drastically reduce donor availability, even though such harmful mutations are extremely rare.
