Sperm from man with rare cancer-risk mutation used to create 67 children

The sperm of a man carrying a rare cancer-causing mutation was used to create at least 67 children, 10 of whom have since been diagnosed with cancer, in a case that has highlighted concerns about the lack of internationally agreed limits on the use of donor sperm.

- Hannah Devlin

Experts have previously warned of the social and psychological risks of sperm from single donors being used to create large numbers of children across multiple countries. The latest case, involving children born between 2008 and 2015, raises fresh concerns about the complexity of tracing so many families when a serious medical issue is identified.

"We need to have a European limit on the number of births or families for a single donor," said Dr Edwige Kasper, a biologist at the Rouen University hospital in France, who presented the case at the annual conference of the European Society of Human Genetics in Milan.

"We can't do whole genome sequencing for all sperm donors - I'm not arguing for that. But this is the abnormal dissemination of genetic disease. Not every man has 75 children across Europe."

The case came to light when two families contacted their fertility clinics after their children developed cancers that appeared to be linked to a rare genetic variant. The European Sperm Bank, which had supplied the sperm, confirmed that the variant in a gene called TP53 was present in some of the donor's sperm.