Question: why would we need to now a coure if it is reallty rear?

Werner Muller answered on 11 Nov 2013:

Rare diseases are an interesting problem. Each rare disease is rare but there are many of them. Taken together many people suffer from rare diseases. It is difficult to treat rare diseases as there is not so much work done on rare diseases. Some of the rare diseases are really bad for the people who have such diseases and any treatment would be most welcomed. It may seem unfair if we would only treat patients with a disease that is common.