Title of paper: Orphan diseases and drugs
Author: Randhawa GK
Department of Pharmacology,Government Medical College, Amritsar, Punjab, India
How to cite this article:
Randhawa GK. Orphan diseases and drugs. Indian J Pharmacol 2006;38:171-176
How to cite source URL:
Randhawa GK. Orphan diseases and drugs. Indian J Pharmacol [serial online] 2006 [cited 2006 Jun 13];38:171-176. Available from: http://www.ijp-online.com/article.asp?issn=0253-7613;year=2006;volume=38...
The World Health Organization defines orphan diseases, as all pathological conditions, affecting 0.65-1 out of every 1000 inhabitants. They are usually not studied for their pathophysiology or for newer therapeutic options, as these are not economically viable.
The Orphan Drug Act was passed on January 28, 1983 by USA to stimulate the research, development and approval of those products that treat orphan diseases. Till date, 11 drugs (4.87%) for tropical infectious diseases have been designated with orphan drug status and as many drugs for other infectious diseases.
Several drugs with orphan status are used in the treatment of diseases that no longer meet orphan status criteria, such as AIDS and end-stage renal disease. Understanding of the human genome, nuclear cloning, rational drug designing and application of high throughput screening in drug discovery programs, might lead to new drug discoveries for orphan diseases. Hence, there is hope in future for patients neglected by for-profit drug discovery efforts.
The World Health Organization defines orphan/rare diseases as, 'all pathological conditions that affect 0.65-1 out of every 1000 inhabitants'. The EU defines a rare disorder as one with a prevalence of 5: 10,000 Europeans; the USA accepts it as an ailment affecting fewer than 2,00,000 Americans (with an incidence of less than 1/5,000 in the general population); Japan has the limit at 50,000 Japanese patients and Australia at 2000 Australian patients. There are approximately 6,000 orphan diseases, out of which 80% are genetic. These diseases are very much like children without parents and as such, require special effort for the development of their treatment options. But they are usually not studied for their pathophysiology or for newer therapeutic options, as the inputs are not economically rewarding. Hence, treatment and diagnostic methods also have not yet been fully developed for them.
Many orphan diseases are lesser known, like Juberg Marsidi syndrome (a genetic disorder of childhood that leads to severe mental retardation, abnormal bone growth resulting in the disfiguring of the head and body and loss of hearing), Hermansky-Pudlak syndrome More Details (a group of genetically heterogeneous disorders which share the clinical findings of oculocutaneous albinism, platelet storage pool deficiency and ceroid lipofuscinosis), Werdnig Hoffman disease (a fatal, fetal disease similar to amyotrophic lateral sclerosis (ALS), Omenn's syndrome (absence of mature B and T cells, children being born with late-stage ALS-like symptoms), Fabry's disease (an X-linked lysosomal-storage disorder due to deficiency of galactosidase A), Lambert-Eaton myasthenic syndrome (an autoimmune disease of peripheral cholinergic system resulting in muscle weakness due to impaired acetylcholine release) and many more like Aarskog syndrome, Adams Nance syndrome, Bagatelle Cassidy syndrome, Bamforth syndrome, Ballard syndrome and Bahemuka Brown syndrome .
There are some familiar orphan/rare/neglected diseases, like Alzheimer's disease, ALS , Crohn's disease, Hodgkin's disease, leukemia ( many forms ), multiple sclerosis, Huntington's disease, sickle cell disease, muscular dystrophy, myasthenia gravis and spinal cord injury . All disorders due to genetic defects in development (like spina bifida, Turner's syndrome, Klinefelter's syndrome, cleft lip and palate ) and deficient enzymes (like cystic fibrosis, respiratory distress syndrome, Gaucher's disease, hemophilia ), are considered orphan diseases. Tropical infectious diseases like malaria, leprosy, tuberculosis and leishmaniasis with lesser incidence in developed countries, may also be considered as orphan diseases there.
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