Although there is no consensus on the definition of rare diseases (RD), the European Union (EU) considers a disease rare when it affects no more than one person in 2000 (Regulation (EC) No 141/2000 1999). RDs are serious, chronic, and often life-threatening conditions. It is widely accepted that national patient registries are vital instruments in the centralized management of RDs (Rodwell and Aymé 2015). However, no single country and national registry has sufficient resources to combat all RDs effectively. Over two decades, the EU has worked to establish e-health-based European Reference Networks (ERNs) to support cooperation among the national registries (European Commission official website, https://ec.europa.eu/health/ern_en). The first 24 ERNs were launched in 2017, involving more than 900 highly specialized healthcare units. They are virtual networks involving doctors and registries across Europe, providing three e-health and telemedicine tools: the ERN Collaborative Platform, the ERN Clinical Patient Management System, and the ERN public website (Conference report of the 3rd conference on European Reference Networks 2017).

In this communication, we conclude that ERNs represent e-health and telemedicine implementation at the highest level