Sperm Donor's Hidden Cancer Gene Passed to Dozens of Children

A single sperm donor has fathered nearly 200 children while unknowingly carrying a serious cancer gene. The discovery has shocked families across Europe and exposed major gaps in international fertility regulations. For 17 years, multiple European clinics used the man's sperm. He was unaware he carried a hereditary mutation in a gene called *MUTYH*. This condition greatly increases the risk of colorectal cancer. The donor’s genetic condition was only discovered after several of his biological children developed cancer as young adults. Health authorities have now contacted many of the affected families. The case has triggered urgent calls for reform. Experts demand mandatory, advanced genetic screening for all sperm and egg donors. They also advocate for strict, international limits on how many children one donor can father. Currently, these rules vary wildly by country. Clinics involved are reviewing their procedures. The incident highlights a hidden risk in the global fertility industry, where genetic information can be incomplete.