What are rare diseases?

Rare diseases are diseases that are potentially fatal or chronically debilitating, that affect less than 5 in 10,000 persons in the European Union (EU).

Currently 5,000-8,000 rare diseases have been identified, according to different classifications. They affect 6-8% of the EU population (27-36 million European citizens), 50-75% of them children.
Approximately 80% of rare diseases have a genetic cause, while the remainder have degenerative, infectious and proliferative causes.

In Portugal, there are an estimated 700,000 persons affected, with some 50 diseases being treated effectively and rationally.