My watch list  

Rare disease

A rare disease (sometimes known as an orphan disease) has such a low prevalence in a population that a doctor in a busy general practice would not expect to see more than one case a year. Rare diseases, including those of genetic origin, are life-threatening or chronically debilitating diseases which are of such low prevalence that special combined efforts are needed to address them.



As a guide, low prevalence is taken as prevalence of less than 5 per 10,000 in the community [1].

The NIH's Office of Rare Diseases states that, "an orphan or rare disease is generally considered to have a prevalence of fewer than 200,000 affected individuals in the United States" [2].

Rare diseases can vary in prevalence between populations, so a disease that is rare in some populations may be common in others. This is especially true of genetic diseases and infectious diseases. An example is cystic fibrosis, a genetic disease: it is rare in most parts of Asia but relatively common in Europe and in populations of European descent. Many infectious diseases are prevalent in a given geographic area but rare everywhere else. Other diseases, such as many rare forms of cancer, have no apparent pattern of distribution but are simply rare.

Eurordis (European Organisation for rare Diseases) estimates that there exist between 5,000 and 8,000 distinct rare diseases, affecting between 6% and 8% of the population.


Rare diseases are usually chronic and life-threatening. This is so because less severe rare illnesses are seldom identified as such. Eurordis estimates that at least 80% of them have identified genetic origins. Other rare diseases are the result of infections and allergies or due to degenerative and proliferative causes. Symptoms of some rare diseases may appear at birth or in childhood, whereas others only appear once adulthood is reached.

See also

List of rare diseases

  • List from Health on the Net Foundation, available in several languages
  • List from National Instutes of Health
  • List from Orphanet (change the last two letters of the link to choose your language: ES, DE, ...)
  • [3] A blog about rare diseases.

Rare diseases organizations


  • en-rbd -- Rare Bleeding Disorder Database - European network
  • Eurordis -- European Organization for Rare Diseases
  • EUROCAT - EUROCAT: European network of population based registries for congenital anomalies.
  • List of projects funded by year.
  • Key documents.
  • DG SANCO Task Force on Rare Diseases; Two day conference on Rare Diseases 2005
  • DG RESEARCH, TECHNOLOGICAL DEVELOPMENT AND DEMONSTRATION 6TH FRAMEWORK PROGRAMME (2002-2006): Life sciences, genomics and biotechnology for health.
  • Orphanet: database of rare diseases.
  • Orphan medicinal products.
  • Committee for Orphan Medicinal Products (COMP) of the European Agency for the Evaluation of Medicinal Products (EMEA).
  • Siere: Spanish Information System on Rare Diseases (in Spanish)
  • ICRDOD -- Information Centre for Rare Diseases and Orphan Drugs
  • Rete Regionale per le Malattie Rare - Regione Lombardia - Italy
  • rbdd -- RBDs - international registry


  • National Organization for Rare Disorders
  • Uplifting Athletes, Inc.

Rare diseases information

  • -- Information retrieval portal that integrates genetic and medical information
  • NIH's Genetic and Rare Diseases Information Center
  • Rare / Orphan Diseases at
  • Rare Diseases Clinical Research Network
  • "Enfermedades raras: un enfoque práctico" (book in Spanish)
  • ICRDOD -- Information Centre for Rare Diseases and Orphan Drugs
  • en-rbd -- Rare Bleeding Disorder Database - European network

Scientific Journals

  • Orphanet Journal of Rare Diseases, open-access and online
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Rare_disease". A list of authors is available in Wikipedia.
Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE