At the annual conference of the European Society of Human Genetics in Milan, biologist Dr. Edwige Kasper from the University Hospital of Rouen presented a case involving a sperm donor who unknowingly carried a rare mutation of the TP53 gene associated with Li-Fraumeni syndrome, a severe hereditary cancer predisposition. Between 2008 and 2015, this donor fathered at least 67 children across Europe through the European Sperm Bank.
The case came to light when two families independently contacted fertility clinics after their children were diagnosed with cancers known to be associated with the TP53 gene mutation. Genetic and pediatric departments across Europe traced their clients and conducted tests on 67 children from 46 families in eight European countries. Of those children, 23 were found to be carriers of the TP53 gene mutation.
Ten of the donor's children developed cancer, including cases of leukemia and non-Hodgkin lymphoma, and are being closely monitored for early signs of disease. The TP53 gene is responsible for producing a protein called p53, which helps cells repair DNA damage or triggers cell death. A mutation in this gene can prevent this function, leading to uncontrolled cell division and tumor formation.
"We cannot sequence the whole genome for all sperm donors—I do not support that," stated Dr. Kasper, but noted that this situation "leads to an abnormal spread of genetic diseases. Not every man has 75 children across Europe."
The European Sperm Bank implements a voluntary limit of 75 families per donor, but this case has prompted calls for international limits and better tracking systems for donor sperm. Experts warn that the international use of sperm complicates the identification and notification of families when a serious medical problem, such as a hereditary cancer predisposition, is discovered.
"The issues at stake here relate to the large number of affected children—which would have been limited if used only within one country according to local limits—and the challenge of tracing the families, which may now span multiple countries," said Professor Nicky Hudson from De Montfort University in Leicester, England.
At the time of the donation in 2008, the rare variant of the TP53 gene was not known to be associated with cancer, and the sperm bank specified that no link to cancer had been established. "Scientifically, it is simply impossible to detect mutations that cause diseases in a person's gene pool if you don't know what you're looking for," said Julie Paulli Budtz, a representative of the European Sperm Bank, adding that the donor had been thoroughly screened.
Children carrying the TP53 gene mutation are advised to have regular health check-ups, including whole-body MRI scans. In adults, follow-up is recommended with breast MRI scans and abdominal ultrasounds. Dr. Kasper detailed the follow-up protocol, emphasizing the importance of early detection to improve survival chances.
The case has shocked the medical community and highlighted concerns about the lack of internationally agreed limits on the use of donor sperm. While some countries impose limits on how many children can be born from a single sperm donor, others do not.
"We need a European limit on births per donor. One man cannot have 75 children scattered across Europe," said Dr. Kasper, advocating for establishing a cross-border limit on the number of children per donor.
"This is an abnormal dissemination of genetic diseases. Not every man should conceive 75 children across Europe," emphasized Dr. Kasper. She noted the challenges of ensuring the safety of assisted reproductive technologies when biotechnology touches human life, calling for coordinated and strict supervision.
The preparation of this article relied on a news-analysis system.