Sperm donor with cancer gene mutation sparks regulatory concerns

Ten children conceived from the same sperm donor have developed cancer, highlighting problems with regulating sperm donation internationally.

In findings presented at the European Society of Human Genetics' annual conference in Milan, Italy, it was shown that this was the result of a genetic variant passed on by the sperm donor. However, the variant was not known when the donor provided sperm in 2008, and tests at the time would not have detected it.

Dr Edwige Kasper from Rouen University Hospital in France, told the conference: 'This is the abnormal dissemination of genetic disease.... We need to have a European limit on the number of births or families for a single donor.'

Dr Kasper was approached in 2023 by a French clinician, whose patient had been contacted by the sperm bank about a genetic variant found in their donor's sperm.

The variant was in the TP53 gene, which is known to be associated with Li-Fraumeni syndrome, a rare condition that causes significantly increased risk of cancer at an early age. However, the variant in question was of unknown significance at the time, and so it was unclear whether it would lead to an increased risk of cancer.

Dr Kasper analysed the variant and 'came to the conclusion that the variant was probably cancer-causing and that children born from this donor should receive genetic counselling'.

Efforts are ongoing to identify people conceived with sperm from this donor, so that they can receive appropriate testing and care. The donor himself is believed to be in good health, and has not had cancer.

There is no suggestion that proper screening procedures were not followed when the donor was recruited, but questions have been raised about the large number of children who might be conceived with the sperm of a single donor. The European Sperm Bank, which supplied the sperm in this instance, has a limit of 75 families per donor.

The number of births to date that have resulted from the sperm of this specific donor has not been disclosed. However, it is known that there have been at least 67 such births across eight European countries between 2008 and 2015, and that at least 23 of these 67 people carry the variant.

Many countries limit the number of children, or the number of families, that can be created with gametes from a single donor. In the UK, for example, there is a limit of ten families. However, such limits are not necessarily imposed across Europe. Sperm from a donor who has reached the limit in one jurisdiction might continue to be provided to people in other jurisdictions (see BioNews 1222, 1240, 1241, 1253, 1278 and 1283).