They generally involve a number of organs and affect the sufferers' physical capacities, metal abilities and sensory and behavioural qualities. The condition may be visible from birth or childhood, but there are some that do not become apparent until adulthood. They are serious or very serious, chronic and usually degenerative diseases and they have great repercussions on the whole family.

There are currently more than 7,000 different rare diseases that directly affect the everyday lives of more than 30 million people in Europe alone. Living with a rare disease is a learning experience every day for the patients and their families. Although they have different names and symptoms, rare diseases affect the everyday lives of the patients and their families in a similar way.

The Hospital de Sant Pau is a member of the Rare Disease Platform and is home to the head office of the European Organisation for Rare Diseases (EURORDIS), located in the Art Nouveau building. 

The European Reference Networks (ERN) enable specialist professionals and centres in different countries share knowledge.

ERNs have to apply the criteria of the European Union (EU) to deal with rare diseases that require specialist treatment, acting as research and knowledge centres that treat patients from other countries within the EU and ensure the availability of treatment facilities as required.

The Hospital de la Santa Creu i Sant Pau currently participates in:

• ERN, European Commission 
• Rare adult cancers
• Rare neuromuscular diseases