A UK cross-national investigation has revealed that a sperm donor carried a gene mutation that greatly increases cancer risk. His sperm was used to assist pregnancies across Europe, resulting in at least 197 children, with several of them developing cancer and at least one tragically passing away.
Experts bluntly stated that the incident is shocking, but "it is impossible for sperm to be 100% safe."
According to the BBC, the anonymous man began donating sperm as a student in 2005, receiving payment, and his sperm was subsequently used for 17 years. At the time, he appeared healthy and passed related screenings; however, investigations found that a DNA mutation had occurred before his birth, damaging the key cancer-prevention gene "TP53."
The investigation was carried out jointly by 14 public broadcasters, including the BBC. Investigators pointed out that most people do not carry the dangerous version of the TP53 gene, but up to 20% of the man's sperm carried the mutation. Children conceived with his sperm have this variant in all their cells, resulting in Li-Fraumeni syndrome, which increases the lifetime risk of multiple cancers to as high as 90%.
The European Sperm Bank emphasized that neither the donor nor his relatives had any medical history, and such mutations "cannot be proactively screened out in advance via genetic screening." Once a problem is discovered, related sperm will be "immediately blacklisted."
Among the 67 children already identified, 23 carry the variant gene, and 10 have been diagnosed with cancer. Subsequent reports from medical staff and families revealed that the donor also had children himself, raising the number of affected children to at least 197.
The investigation found that the man's sperm was used by 67 clinics in 14 countries. One mother who received his sperm said in an interview that her child is now 14 and has been confirmed to carry the mutant gene. She said she does not resent the donor, but finds it hard to accept that the sperm acquired at the time was “unclean, unsafe, and carried risks,” because her child and family may face a lifetime shadow from cancer.
Currently, most countries in the world have set no limit on the number of times a donor’s sperm can be used, though some countries do have regulations. For example, Belgium limits a donor to helping six families, while the UK limits it to ten families.
However, Allan Pacey, Vice Dean of the School of Biological Sciences and Health at the University of Manchester, noted that countries are increasingly relying on large international sperm banks, and nowadays half of the sperm used in the UK is imported.
Speaking about this case, Pacey admitted the incident is extremely frightening for families and related parties, but "making sperm completely safe is impossible."
He said under the current screening system, only 1% to 2% of men qualify as sperm donors; if the standards are raised further, the number of eligible donors will be even lower.