Rare gene mutation in sperm donor linked to cancer in 10 children
The donor, who was healthy at the time of donation, carried a mutation in the TP53 gene, which is linked to Li-Fraumeni syndrome.
A sperm donor who unknowingly carried a rare cancer-related genetic mutation fathered at least 67 children across Europe, ten of whom have now developed cancer, prompting urgent calls for stricter rules on sperm donation.
The donor, who was healthy at the time of donation, carried a mutation in the TP53 gene, which is linked to Li-Fraumeni syndrome, a rare disorder that significantly increases the risk of cancer.
His sperm was used between 2008 and 2015 to help conceive children from 46 families in eight countries: Belgium, Denmark, France, Germany, Greece, Spain, Sweden and the United Kingdom.
The case was revealed by Edwige Kasper, a biologist at Rouen University Hospital in France, during a presentation at the European Society of Human Genetics conference held in Milan on Saturday.
"At the heart of the problem seems to lie the regulation, or maybe the lack of regulation, of the number of births by a single donor," she said.
So far, ten of the donor-conceived children have been diagnosed with cancers such as brain tumours and Hodgkin lymphoma. Another 13 children carry the same TP53 mutation but have not yet developed cancer.
All of them now face ongoing medical checks due to their increased cancer risk, as well as a 50 percent chance of passing the gene on to their own children.
“The follow-up protocol involves whole-body MRI scans, MRI scans of the brain and, for adults, of the breast, ultrasound examination of the abdomen, and a clinical examination by a specialist," said Kasper in a press release.
"This is heavy and stressful for carriers, but we have seen its effectiveness in that it has enabled early detection of tumours and thus improved patients’ chances of survival."
The sperm donor gave samples only to the European Sperm Bank, a private sperm bank based in Denmark. Julie Paulli Budtz, vice-president of corporate communications at the bank, said the institution was "deeply affected by this case."
"The donor has been thoroughly tested even above the required standards, but preventative genetic screening is reaching its limits here,” she said.
"Every human being has about 20,000 genes, and it is scientifically simply not possible to detect disease-causing mutations in a person’s gene pool if you don’t know what you are looking for."
Budtz also noted that there is currently no unified rule on how many children can be born from one donor.
"This is also why, in addition to following national pregnancy limits, we have proactively implemented our own international limit of 75 families per donor," she said.
Across Europe, rules on donor limits vary widely. France allows 10 births per donor, Denmark permits 12, and Germany allows up to 15.
"There is a major issue here concerning a lack of harmonised regulation across Europe," said Kasper.
"We need proper regulation at European level to try to prevent it happening again, and to implement measures to ensure a worldwide limit on the number of offspring conceived from the same donor."
