Learn all about the European Reference Networks and how you can be involved.

If you wish to contribute please email with your information.

ENDO-ERN 'cherishes' rare endocrine disorders

What is rare, a unique painting, a unique building, deserves extra attention. This is also the case with rare diseases. The development and dissemination of knowledge about these diseases require extra attention. For this reason, for several years now the EU has had ERNs, European Reference Networks. These are  virtual networks in which doctors and patients in Europe share their knowledge of and experiences with rare diseases. ENDO-ERN ‘cherishes’ the rare endocrine disorders. Take a look at


It sounds paradoxical: rare diseases are not rare at all. After all, in the Netherlands there are an estimated one million people diagnosed  with a rare disease. Moreover, in the European Union there are in total around 30 million people diagnosed with a rare disease . The rarity of the rare diseases only becomes clear when you consider that this is a collection of many thousands of different disorders. For each disorder, we are talking about a few dozen to, at most, a few thousand patients (in the Netherlands). Officially, a condition is qualified as ‘rare’ if the disease occurs in less than 1 in 2000 people. Translated into Dutch terms, this means that a disease is rare if fewer than 8,500 patients in the Netherlands are diagnosed with the disease.

The fact that a disease occurs in only a few people is in itself pleasant. The fewer people suffer from a disease, the better. However, for people who do suffer from a rare disease, its rarity is a (major) disadvantage. For them, the medical circuit is sometimes a real obstacle course. To start with, it often takes (much) longer before the disease is recognized and the correct diagnosis is made. For example, an GP in the Netherlands has in average only once in every 20 years  a patient with a pituitary gland diseasein his pratice. Particularly if the rare disease has  symptoms that also fit a much more common disorder, a doctor will initially focus  on this more common disorder.


Once the correct diagnosis has been made – which can sometimes take years – the second hurdle follows: the patient often has to undertake an often difficult  search to find a medical specialist who has specialized in the rare disease and  therefore is aware of all aspects of the disorder. For example, not every internist always has all the knowledge about the treatment of Cushing’s syndrome or thyroid cancer. Moreover, it is not uncommon that the scientific knowledge about the development and optimal treatment of rare diseases is limited. After all, unknown,  unloved; applies also  to (investing in) scientific research. Finally, the patient with a rare disease, more than people with a common disorder such as asthma or diabetes, encounters  more incomprehension and ignorance of the environment which makes coping with the  disease certainly not easier.


In recent years, ‘Brussels’ has also become aware of the ‘disadvantages’ of people with rare diseases. In 2017, this led to the foundation of European Reference Networks (ERNs), in Dutch: Europese Referentie Netwerken . There are 24 ERNs (in 2019), ranging from a network focusing on epilepsy (ERN EpiCare) to a network focusing on organ transplantation in children (ERN TRANSPLANT CHILD). The aim of each network is to centralise all knowledge and experiences of physicians and patients (organisations) of a particular rare disease to make this knowledge and experiences available to other physicians and patients. This should enable all patients with a given rare disease to benefit from the most recent scientific insights about their disease anywhere in Europe and to receive the best possible treatment. Perhaps not at home, but certainly with the help of colleagues from abroad. Less specialised doctors can use the network to consult  (European) colleagues who are more specialised in a particular rare disease. This means it’s no  no longer the patient who has to search  for a doctor who understands all ins and outs of his rare disease. Through the network, the local doctor is able to get advise for  the doctor who knows best  about this particular condition. So, the knowledge and expertise come to the patient, rather than the other way around. It is still a dream of every person affected by a rare disease, that all doctors advise the patient with a rare disease adequately to go to an expert centre.


One of the ERNs is ENDO-ERN, which – as its name suggests – focuses on endocrine diseases. Over 70 centres of expertise from almost 20 countries are united in ENDO-ERN. This network deals with rare diseases of the adrenal gland, thyroid, pituitary gland and (rare) disorders of the calcium and phosphate balance in the body, genetic disorders of the glucose and insulin balance in the body, disorders caused by genetically determined endocrine tumors, genetically determined obesity and growth disorders and rare disorders of sexual development such as DSD. In the Netherlands 7 hospitals are designated  as EXPERTISE centres on one or more rare  adrenal, thyroid or  pituitary diseases: Amsterdam UMC, Erasmus MC (Rotterdam), LUMC (Leiden), Máxima Medisch Centrum (Veldhoven), Radboudumc (Nijmegen), UMCG (Groningen) and UMCU (Utrecht). In turn, these centres of expertise are part of regional networks in the Netherlands so that every patient can receive state of the art care.


However, ENDO -ERN is not only intended as a ‘passive’ platform for the exchange of knowledge on rare endocrine diseases. The international contacts between doctors will also stimulate (the improvement) of medical thinking and treatment on these conditions, stimulate new scientific research on these conditions, stimulate the development of e-health and ICT applications for these conditions and ultimately improve the quality of care for patients throughout Europe. Patients and physicians also work together to improve or create educational materials, if possible in many  languages, to stimulate dissemination of  information. Parties, both patients and doctors across national borders, will be able to grow closer together thanks to ENDO-ERN.


This improvement in care for patients with pituitary, thyroid or adrenal disorders throughout Europe is, of course, a huge step forward for Dutch patients as well. As a result, they can expect the quality of care to be guaranteed when they are abroad. For example, the European Alarm Card, , make clear you need a some extra attention, is now widely accepted in Europe. to. This will also give you the opportunity to support your choices for a treatment centre.


The voice of the patient is also well heard within the ERNs. . Patient representatives, the so-called European Patient Advocate Group-representatives, in short ePAGs, make part of every ERN. Of the 14 ePAGs within ENDO-ERN, three originate from the Netherlands: Johan Beun (adrenal disorders), Johan de Graaf (pituitary disorders) and Marika Porrey* (thyroid disorders). In addition to giving a voice to the experiences and needs of patients to doctors and researchers, the ePAGs also contribute to establishing and strengthening contacts between patients and their organisations at a European level. For example, the thyroid cancer working group is currently working hard to make available in several languages an information booklet aimed at children whose mothers are being treated for thyroid cancer. Within the pituitary group, a best clinical practice document for the treatment of congenital hypopituitarianism is being prepared. This will also result in patient educational  material in different languages. The stress instructions and emergency cards for people with adrenal disease developed by the Adrenal Society NVACP in collaboration with Adrenal NET can thus be rolled out more effectively throughout Europe.


Thanks to Marten Dooper, the author and

with the cooperation of Marika Porrey, Johan de Graaf and Johan G. Beun the co-authors, co-readers.


(*) To our great regret it has become clear with the publication of this article that Marika Porrey (of the SON) can no longer continue her international work. She stopped her work after the summer of 2019.


October 2019

See also:

WAPO Contacts

WAPO believes that the strength of a global network of national pituitary patient organizations will lead to improved diagnosis, treatment and care for pituitary and adrenal patients worldwide.