Global donor sperm scandal expands as Danish case links 211 children to cancer-causing genetic defect

The number of children born from a single Danish sperm donor carrying a life-threatening genetic mutation has risen to at least 211, according to new findings by Danish broadcaster DR, making it the largest known case of its kind worldwide.

Research by DR, drawing on updated data including records from Greek authorities, confirms the donor—identified only as “Kjeld”—fathered children across 14 countries before his sperm was recalled in 2025 after the discovery of a cancer-predisposing TP53 gene variant. The true figure may be higher, as not all recipient countries have disclosed their numbers.

Several of the children have since died or developed cancers linked to the mutation, which went undetected for nearly two decades. Neither the donor nor the sperm bank, European Sperm Bank, were aware of the defect at the time of donation.

Bioethicists describe the case as unprecedented in scale. Arthur Caplan, a leading US bioethicist, called it “the largest instance I know of where a high-risk disease has been transmitted to so many children” and warned of a “new form of public health crisis at the genetic level.”

No EU-wide limits exist on how many children a single sperm donor can father, allowing cross-border sales of donor material without restriction. Caplan has long argued for caps on donor use, calling the lack of limits “the biggest ethical failure in the entire sperm bank industry.”

Geneticists stress that early identification of affected children could save lives through targeted monitoring. “We can save lives if these children receive the right information and access to screening programs,” said Svetlana Lagercrantz of Sweden’s Karolinska Institute, who has examined several of Kjeld’s offspring as part of the European GENTURIS network for hereditary cancer.

Yet efforts to trace all the children have been hampered by the sperm bank’s refusal to disclose the full number of pregnancies. Edwige Kasper, a French geneticist who has spent over two years mapping the case, said researchers “are pooling all our resources to locate these children, but it’s extremely difficult without knowing how many there are.”

Danish geneticist Karin Wadt, who first contacted European Sperm Bank in 2024 seeking data, described the lack of transparency as “frustrating.” “After the initial round of genetic testing, I have no sense of whether we’re halfway there or still at the beginning,” she said.

The bank has cited GDPR privacy protections for the donor, known only as Kjeld, in declining to share details with researchers or media. In a statement, communications director Julie Paulli Budtz confirmed the bank has provided pregnancy figures to Danish and foreign health authorities but not to independent experts.