An orphan disease is one that has been “orphaned” by the medical and pharmaceutical industries in terms of diagnosis, research and development of treatments due to its rarity.
The majority of these diseases have a genetic basis and are extremely rare, occurring in as few as 1 in 10,000 people. Many conditions, diseases and syndromes exist that most people have not yet heard of; that many medical professionals are not yet familiar with; and for which treatment modalities are not yet available.
Making an accurate diagnosis of an orphan disease is particularly difficult, because as a group they are characterized by a diversity of disorders and symptoms which vary from disease to disease and patient to patient. Relatively common symptoms can also hide underlying rare diseases, leading to misdiagnosis. While symptoms for some diseases appear at birth, others appear in childhood and still others only once adulthood is reached, adding to the difficulty of diagnosis.