The sperm of the donor at risk of cancer was used to design at least 67 children across Europe | Cum

The sperm of a man bearing a rare transfer cancer cancer has been used to conceive at least 67 children, 10 of whom have since received a cancer diagnosis, in a case which highlighted the concerns concerning the lack of internationally agreed limits on the use of the donor sperm.

Experts previously warned the social and psychological risks of the sperm of unique donors used to create a large number of children in different countries. The last case, involving dozens of children born between 2008 and 2015, raises new concerns about the complexity of the tracing of so many families when a serious medical problem is identified.

“We must have a European limit on the number of births or families for a single donor,” said Dr. Edwige Kasper, a biologist at the Rouen University Hospital in France, who presented the case at the annual conference of the European Human Genetics Society in Milan.

“We cannot do a sequencing of the whole genome for all sperm donors-I don’t have it for that,” she added. “But it is the abnormal dissemination of genetic diseases. Not all men have 75 children across Europe. “

The case was revealed when two families independently contacted their fertility clinics after their children developed cancers that seemed to be linked to a rare genetic variant. The European sperm bank, which had provided the sperm, confirmed that the variant of a gene called TP53 was present in some of the sperm of the donor.

The rare variant was not known to be linked to cancer at the time of donation in 2008, would not have been detectable using standard screening techniques, and the donor is in good health. However, the analysis of the Kasper laboratory concluded that the mutation was likely to cause Li-Fraumeni syndrome, one of the most serious hereditary predispositions to cancer.

Kasper said: “I analyzed the variant using population and patient databases, computer prediction tools and the results of functional trials and I concluded that the variant was probably cancer and that children born of this donor should receive genetic advice.”

Simultaneously, a certain number of genetics and pediatrics services across Europe were investigating their own cases, which led 67 children of 46 families in eight European countries tested. The variant was found in 23 children, 10 of whom received a diagnosis of cancer, in particular cases of leukemia and non -Hodgkinian lymphoma.

Children are advised with the risk gene to be monitored with MRI analyzes of whole bodies, MRI of the brain and, as adults, the examination of the breast and the ultrasound of the abdomen.

The European sperm bank, which applies a global limit of 75 families for each sperm donor, said that more than 67 children had been designed using the donor’s sperm, but that its policy was not to confirm the exact number of children for a specific donor. He said all the relevant clinics had been alerted.

Kasper said it was a concern. “Is the total 67? This is a very good question that I asked the sperm bank. They did not mean the denominator of births for this donor,” she said.

Professor Nicky Hudson, of the University of Montfort de Leicester, said that the case underlined the complexity of the challenges that could arise when human gametes have been shipped between countries and used for a large number of beneficiaries.

“The important problems at stake here relate to the large number of children affected – who would be limited except in a country according to local limits – and the challenge of tracing families, who can now extend over several countries,” said Hudson.

“Although these types of cases have fortunately been rare, we must consider the means to limit the possibility that this scenario becomes more frequent in the future by coordinating international practice. At the very least, we need better systems to follow the use of donors and inform the recipients of this. ”

Julie Paulli Budtz, spokesperson for the European Sperm Bank, said: “We are deeply affected by this affair.” She said that the donor had been carefully tested, but that it is scientifically not possible to detect pathogenic mutations in the gene basin of a person if you do not know what you are looking for. “

She added: “We are delighted with the continuous dialogue on the definition of an international mandated family limit and we have pleaded for this on several occasions. This is also why we have proactively implemented our own international limit of 75 families per donor.”