Sperm from donor with cancer-causing gene was used to conceive almost 200 children

"It is a dreadful diagnosis,"

"It's a very challenging diagnosis to land on a family, there is a lifelong burden of living with that risk, it's clearly devasta"

"very small"

"deepest sympathy"

A sperm donor unknowingly carried a mosaic mutation in the TP53 gene present in up to 20% of his sperm, causing Li-Fraumeni syndrome when inherited. The donor began donating in 2005 while a student and his sperm was used for about 17 years across multiple European countries, resulting in at least 197 children. Any child conceived from affected sperm will have the mutation in every cell and faces up to a 90% lifetime risk of cancer, including high childhood cancer risk and later breast cancer. The donor remained healthy and passed screening. Denmark's European Sperm Bank acknowledged excessive use and expressed deepest sympathy, and a very small number of British families used the donor via Denmark.

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