Centres of Expertise and European Reference Networks: key issues in the field of rare diseases. The EUCERD Recommendations.

Background: Rare diseases, because of their intrinsic characteristics - large number of disorders and syndromes, low individual prevalence, severity, often limited information, lack of therapies - can benefit from collaboration and sharing of expertise while maximising the limited resources available for these conditions. Therefore, the development of Centres of Expertise (CEs) and European Reference Networks (ERNs) in this field is crucial.The European Union Committee of Experts on Rare Diseases (EUCERD) has been charged to assist the European Commission with the preparation and implementation of activities in the field of rare diseases in Europe.