Information regarding the TP53 case
In light of recent events and the media coverage related to the TP53 case and family limits, we have gathered a set of resources to help clarify the situation and provide additional context and support.
The TP53 case
For over 20 years, we have supported thousands of people on their path to parenthood, and with the help of our donors, more than 70,000 children across 60,000 families have been born in over 100 countries.
We are deeply touched by the very unfortunate case in which one of our donors has passed on a rare mutation in the gene TP53 to a number of children, and the donor, the children and the families have our deepest sympathy.
When we, in 2023, through a specialized test, confirmed the presence of a mutation in the TP53 gene in one of our donor’s semen, we immediately informed all relevant authorities and all clinics who had used the donor.
This allowed clinics to inform all affected families and provide them with the necessary genetic counselling.
The specific mutation could not have been discovered through preventive screening
While it does not change anything for the affected families, who have our deepest sympathy, it is important to know that the specific mutation is a rare and previously undescribed TP53 mutation, that it is only found in a small part of the donor's sperm cells and not in the rest of the body, as the donor himself is not affected.
This means that the TP53 mutation cannot be detected preventively by genetic screening. It also means that not all children conceived with the help of the donor will have the mutation. That is also why we recommend that all children from the donor are tested.
Our donor screening
Our comprehensive donor screening and selection of donors is the foundation of what we do, and we continuously update and improve our testing to reflect the best medical practices.
All of our approved donors have been through the following screening:
- The quality and number of sperm cells.
- Review of the donor medical history of the donor candidate and his family members.
- Genetic screening for some of the most common ressecive disease e.g. Cystic Fibrosis
- Thorough physical examination
- Personality evaluation
Because of our high standards only 5 percent of the men who show up for a first sperm sample end up becoming sperm donors. It is therefore generally safer to use a donor who has been medically screened than to conceive with someone who has not. It is, however, important to note that no screening can eliminate all risk, and even for the conditions tested, a residual risk will always remain. This reflects the current limits of medical science and available technology.
Our approach to family limits
Since ultimo 2022, ESB has introduced an international family limit of 75 families per donor. With no global or EU-wide standards in place, our limit is based on leading scientific studies and long-standing recommendations from professional bodies such as ASRM, while also closely following and adapting to ongoing and emerging discussions within the donor-conceived community.
We also provide the option to use donors who have given even lower family limits – as far down as one.
We further advocate for the establishment of national and an EU donor registry to ensure both national and European oversight on the number of children a donor has helped conceive.
Pregnancy Slots and future measures
We have, unfortunately, found that the limits have been exceeded in some countries, both in the specific TP53 case and in others. There are various reasons for the exceedances, which are primarily of a technical and administrative nature and we are in dialogue with the authorities in Denmark and Belgium about this.
Over the past years, we have improved – and continue to improve – our control mechanisms to ensure that all donors in use remain below the permitted limits. Already in 2016, we introduced pregnancy slots for donor sperm – also known as quota reservations in the UK – and have since implemented this system in several other markets, including Denmark, the Netherlands, and Belgium. It is a system we developed and were the first sperm bank to introduce.
As part of the Danish Business Association for Egg and Sperm Donation, we have contributed to the development and recent launch of a new Danish sperm donor registry aimed at increasing patient safety. The initiative has, among others, received support from the Danish Council on Ethics.
In retrospect, we wish there had been better coordination and systems between donor banks, clinics and health authorities to reduce the risk of exceeding national limits. Going forward, better coordination and systems between donor banks, clinics and health authorities will support compliance with national limits to an even greater extent.
Q&A
We do not disclose the total number of children conceived using a specific donor, as this is protected under data privacy regulations (GDPR) as the Danish authority consider the total number of children his personal data.
If your donor is the one with a TP53 mutation, your clinic should already have informed you. If you have your donor alias or number, please contact us and we will assist you.
If you do not have your donor number or alias, you will need to contact your clinic and ask them to verify this information. If you no longer have the clinic’s details, or if the clinic has closed, you should reach out to your local health authority for guidance.
The TP53 mutation is extremely rare, and we always conduct an individual medical assessment of every donor in full accordance with recognised scientific practice and applicable legislation. Only about 5% of men who apply to become donors are approved by us.
Therefore, donor-assisted reproduction remains a safer option compared with reproduction without any genetic screening. While no process can eliminate all risk, it is important to emphasise that this specific case is exceptionally uncommon.
In this specific case, the TP53 mutation is a newly arisen, previously undescribed mutation. It occurs as what is known as a gonadal mosaic, meaning that it is present only in a small proportion of the donor’s sperm cells and not in the rest of the body. The mutations of this type are not identified preventively through genetic screening. The fact that the TP53 mutation affects only a small fraction of the sperm cells also means that not all children conceived with help from the donor have inherited the mutation.
At European Sperm Bank, we support the implementation of international regulation that set clear limits on the total number of families a donor can help. We have advocated for this consistently – including at EU level – and have backed the recommendation from among others the Nordic National Ethics Councils. They emphasise that a range of factors and potential conse-quences must be considered when determining these limits; see this position paper.
As there is no mandated limit we have implemented our own international family limit of 75 families per donor. This limit is based on scientific research.
There are several reasons for these exceedances, these are primarily technical and administrative. In hindsight, we wish there had been better coordination and systems in place between donor banks, clinics, and health authorities to minimise the risk of exceeding the national limits. Going forward, improved coordination and systems between donor banks, clinics, and health authorities will further support adherence to the national limits.
For several years, we have actively worked for common standards and a registry at EU level and in Denmark, as well as for an international family limit of 75 families, to create better shared frameworks and regulation of the entire field. We have also implemented measures to strengthen timely reporting from clinics and introduced pregnancy slots to ensure more accurate tracking and compliance across borders
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We know that the TP53 case and media focus might raise further questions. For questions related to the case please contact info@europeanspermbank.com.
