A sperm donor, who unknowingly possessed a genetic mutation significantly elevating cancer risk, has fathered at least 197 children across Europe, according to a comprehensive investigation. Some of these children have already succumbed to the disease, while only a minority who inherit the mutation might live free of cancer. The sperm was not distributed to UK clinics, but the BBC confirms that a 'very small' number of British families, who have been informed, used the donor’s sperm for fertility treatments in Denmark. Denmark’s European Sperm Bank, responsible for selling the sperm, extended its 'deepest sympathy' to affected families and acknowledged that the sperm was used to conceive too many children in some regions.
The investigation was carried out by 14 public service broadcasters, including the BBC, as part of the European Broadcasting Union's Investigative Journalism Network. The sperm originated from an anonymous donor who volunteered at a young age starting in 2005, and it was utilized for approximately 17 years by prospective mothers. While the donor was healthy and passed standard screening processes, some of his cells experienced a mutation before birth, affecting the TP53 gene, which plays a critical role in cancer prevention. Although most of the donor’s body is free of the altered TP53 gene, up to 20% of his sperm carry the mutation. Consequently, children conceived from affected sperm possess the mutation in every cell of their bodies.
This genetic disorder, known as Li Fraumeni syndrome, is associated with an up to 90% probability of developing cancer, particularly in childhood and increasing the risk of breast cancer later in life. Professor Clare Turnbull, a cancer geneticist at the Institute of Cancer Research in London, described the diagnosis as 'dreadful,' adding, 'It's a very challenging diagnosis to land on a family, there is a lifelong burden of living with that risk, it’s clearly devastating.' Individuals with the syndrome require annual full-body MRI and brain scans, alongside abdominal ultrasounds, for tumor detection. Many women choose to undergo preventive mastectomies to diminish their breast cancer risk.
The European Sperm Bank stated that neither the 'donor himself nor his family members are ill,' and such mutations are 'not detected preventively by genetic screening.' They ceased using the donor's sperm immediately after discovering the issue.
Concerns were initially raised by doctors observing cancer cases linked to sperm donation during this year's European Society of Human Genetics meeting. They reported identifying 23 carcinogenic cases out of 67 known at that time, with 10 children already diagnosed with cancer. Through Freedom of Information requests and firsthand accounts from doctors and patients, the investigation reveals a substantially higher number of births from the donor. At least 197 children were conceived with his sperm, but this may not be the ultimate tally as comprehensive data from all countries is unavailable. Additionally, the number of children bred carrying the mutation remains uncertain.
Dr. Edwige Kasper, a cancer geneticist from Rouen University Hospital in France, who shared initial findings, conveyed to the investigation: 'We have many children who have already developed cancer. Some of these children have already developed two different cancers, with some having died at a very young age.' Céline, not her real name, is a single mother in France whose child, now 14, inherited the mutation through the donor’s sperm. She was urgently advised by her Belgian fertility clinic to screen her daughter for the mutation.