Sperm from a donor who unknowingly carried a cancer gene has been used to conceive almost 200 babies in Europe, according to an investigation by the BBC and 14 other publicly owned news organizations, along with members of the European Broadcasting Union’s Investigative Journalism Network.
Some children fathered by the donor have already died, and only a minority who inherit the gene will not have cancer in their lifetime, the British outlet reported.
The sperm was not used in the U.K., but a small number of British families who underwent fertility treatment in Denmark used the donor.
Denmark’s European Sperm Bank sold the sperm and said families affected had its “deepest sympathy,” adding that the sperm was used to conceive too many babies in some countries.
The sperm belonged to an anonymous man who was paid to donate in 2005, when he was 17 and a student. His sperm was used for about 17 years.
The man is healthy, and was healthy at the time of donation — he passed the necessary screening checks to donate, but some of his cells’ DNA mutated before he was born, damaging the TP53 gene, which plays a crucial role in preventing cancerous cells from spreading.
While most of the donor’s body does not contain the damaged gene, up to 20 per cent of his sperm do, the investigation found.
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Any baby conceived from the affected sperm will carry the mutation in every cell in their body, leaving them with a genetic disorder known as Li-Fraumeni syndrome, which significantly increases a person’s chance of developing cancer in their lifetime, including brain tumours and childhood cancers such as leukemia.
“It is a dreadful diagnosis,” Prof. Clare Turnbull, a cancer geneticist at the Institute of Cancer Research in London, told the BBC. “It’s a very challenging diagnosis to land on a family, there is a lifelong burden of living with that risk, it’s clearly devastating.”
There is a 90 per cent chance that people with Li-Fraumeni syndrome will develop cancer, according to the investigation, tethering them to a lifetime of yearly MRI scans and ultrasounds. Women with the mutation may also opt to undergo a double mastectomy to reduce the risk of developing breast cancer.
The European Sperm Bank explained that a mutation of this kind is “not detected preventatively by genetic screening,” and that the donor sperm were removed from circulation after the mutation was discovered.
Doctors treating children with cancer linked to sperm donation expressed their concerns at the European Society of Human Genetics this year.
They reported finding 23 children with the mutation among the 67 known to have been born to the donor at the time. Ten of the 67 already had cancer diagnoses.
The investigation found that at least 197 children have been born using the donor’s sperm.
Dr. Edwige Kasper, a French cancer geneticist, who first presented the data, told the investigation, “We have many children that have already developed a cancer.”
“We have some children that have developed already two different cancers and some of them have already died at a very early age,” she added.
Parents of children who were conceived using the donor have been contacted by their clinics and are being urged to have their children screened.
Sixty-seven fertility clinics used the donor’s sperm in 14 different countries.
There is no single law capping the number of times a donor’s sperm can be used, though individual countries set their own limits, which were breached in this case.
In Belgium, a sperm donor is only supposed to be used by six families. Instead, 38 women gave birth to 53 children by the donor, according to the report.
In Canada, there is no federal cap on the number of families that can use one sperm donor, but clinics and provinces can set their own rules.
For example, at the Quebec Sperm Bank, donors are limited to 10 families.
There is no legal limit in Ontario, though the province, along with British Columbia and Alberta, has legislation that waives parental responsibility for the donor of the conceived child, according to Fertility Law Canada.
According to American Society for Reproductive Medicine guidelines, sperm donors should be limited to 20 to 25 offspring per donor to reduce the risk of mutations and incest.
Global News has reached out to Health Canada and the Minister of Health’s office for further information on sperm testing and screening in Canada.
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