A problem is happening in Europe. It is about a man who gave sperm. This happened for many years.
This man had a gene. This gene can make him sick. It can make children sick too.
Many children were born. They used sperm from this man. Some children are now sick.
This is a sad story. Families are worried. They want to know why.
Fertility clinics help people. They help make babies. But they must be careful.
This shows a problem. Tests for donors are not good. They need to be better.
Health people are talking. They want better rules. They want to help families.