What is the distinction of rare and very rare?

Question

how big is the gap say for a disease that is rare and a disease that is very rare?(such as Asperger's syndrome)

Answer 1

There is no quantitative distinction, but there is a qualitative distinction.  A rare disease is one in which there is at least some active funding to research its treatment.  There may be drugs manufactured to treat it, and they are probably expensive to the point insurance companies try to find ways to avoid paying for them.

A very rare disease is one in which there is almost no funding for research, and probably very little available treatment.  If there is a drug to treat the disease, it is probably exceptionally expensive and insurance companies are quite loath to pay for it.

Answer 2

dont know....may be twice as much.

regards