Rare diseases are diseases, conditions, syndromes or disorders that affect a small number of people compared to the general population. And because of their rarity, they pose specific questions. In Europe, it is considered that a disease is rare when it affects 1 person in 2,000. A disease can be rare in one region, but common in another. There are also many common diseases whose variants are rare.



The 29th February 2016 is the Rare Disease Day.

There are thousands of rare diseases. Until now, were already discovered 6000-7000 rare diseases and new diseases are regularly described in the scientific literature. The number of rare diseases depends on the degree of specificity used to classify the different disorders. So far in the field of medicine, disease is defined as an altered state of health, presented with a unique pattern of symptoms and with a single treatment. 70% of patients with rare diseases suffer some kind of disability.

From orphanet