Rare diseases are the diseases or the condition of that particular member .that affect fewer people.
These are defined as drugs for rare diseases. the treatment of these conditions has been orphaned or discontinued the reason of there is not financial support for the development of the drug. So these are the drugs that are not developed by the pharma industry but respond to public health.
These orphan drugs are medical products that are developed for the treatment of rare diseases. A rare disease is a condition that affects a small percentage of the population.