Rare endocrine conditions affect a small proportion of the population and often require specialised multidisciplinary care. Due to the rarity of these conditions, available clinical knowledge is frequently limited and fragmented. Disease registries are essential tools for collecting systematic data, understanding disease characteristics, improving clinical care, and supporting research collaborations across countries.

To describe the current landscape of European registries for rare endocrine conditions and to evaluate their characteristics, including disease coverage, data collection approaches, and potential opportunities for collaboration and harmonisation.

A survey was developed and distributed among European experts involved in the care of patients with rare endocrine conditions. Information was collected regarding existing registries, including their scope, participating centres, geographical coverage, patient populations, data elements collected, and governance structures.

The survey identified multiple registries across Europe covering a wide range of rare endocrine conditions. Considerable variation was observed in registry design, data collection methods, and clinical information captured. Many registries were disease-specific, while others covered broader groups of endocrine conditions. The findings demonstrated the need for improved coordination, standardised data collection, and collaboration between existing registries to maximise their value for research and clinical care.

This overview highlights the fragmented landscape of European registries for rare endocrine conditions and demonstrates the need for harmonised approaches to registry development. The findings provided an important foundation for the development of the European Registries for Rare Endocrine Conditions (EuRRECa), supporting international collaboration and systematic data collection.

High-quality registries are essential for improving knowledge and care for patients with rare endocrine conditions. This study identified important challenges and opportunities in existing European registries and contributed to the establishment of a coordinated framework for rare endocrine disease data collection through EuRRECa.