Archive · 11 Dec 2025
Danish Sperm Donor with Cancer Mutation Linked to 197 Children
A man in Denmark donated sperm to help people have babies.
He had a special problem in his sperm that can cause cancer, but he didn't know it.
The sperm was used to make 197 babies in different countries.
The problem was found in 2023, and now they won't use his sperm anymore.
Not all the babies have the problem, and the man himself is healthy.
The sperm bank is very big and has helped make over 70,000 babies.
Some of the babies with the problem have already gotten very sick, and some have died.
The moms and dads of these babies are very sad and worried.
A Danish sperm donor, known as Kjeld, was found to carry a rare TP53 mutation in his sperm that increases cancer risk.
His sperm was used to conceive at least 197 children in 14 countries between 2005 and 2022.
The mutation was not detectable by prior genetic screening and was only found in a small part of the donor's sperm cells.
The European Sperm Bank discovered the mutation in late October 2023 after initial alerts in April 2020 and 2023.
Out of 67 known cases, 23 children were identified with the mutation, 10 of whom had already developed cancer, with some deaths reported.
- Who
- A Danish sperm donor using the alias Kjeld, who is an asymptomatic carrier of a genetic mutation increasing the risk of cancer.
- What
- The donor's sperm was used to conceive at least 197 children worldwide before the discovery of the genetic mutation.
- When
- The mutation was discovered in late October 2023, with initial alerts in April 2020 and 2023. The donor was active from 2005 to 2022.
- Where
- The sperm was sold to 67 clinics in 14 countries, with 99 children conceived in Denmark alone.
- Why
- The mutation was not detectable by prior genetic screening and was only found in a small part of the donor's sperm cells.
- Donor Alias
- Kjeld
- Mutation Type
- TP53
- Number of Children
- 197
- Countries Affected
- 14
- Clinics Involved
- 67
- Donor Active Years
- 2005-2022
- Sperm Bank
- European Sperm Bank
- Mutation Detection Year
- 2023
- Children with Mutation
- 23
- Children with Cancer
- 10
