Facebook Twitter Instagram You Tube Pinterest LinkedIn RSS Podcasts Video Library Blog
 - Northwestern Memorial Hospital - Chicago

Rare and Orphan Diseases

What is an “orphan” disease?

According to the Office of Rare Diseases Research at the National Institutes of Health, a rare or “orphan” disease is one with a prevalence of fewer than 200,000 individuals in the United States. Rare diseases by their very nature are difficult to diagnose, since few physicians have seen them and they are unlikely to occur. Typically, in the presence of generic symptoms, more common causes are ruled out before rare conditions are considered. Since few people are affected, pharmaceutical companies devote their research and development budgets to diseases and conditions that affect millions of people, rather than a few thousand.

The Internet and social media have greatly improved the lives of patients and families who suffer from rare conditions. Patients from around the world now band together for support and advocacy. Advances in molecular biology and human genetics yield many more specialized therapies than ever before.

Internet Resources

Office of Rare Diseases Research (ORDR)
Part of the National Center for Advancing Translational Sciences, ORDR is a first stop for anyone seeking information about a rare condition. Links to patient advocacy groups, scientific conferences, research and clinical trials, and much more is available here.

Rare Disease Day USA
This website is the official U.S. Rare Disease Day website. Rare Disease Day is an international advocacy day established to bring widespread recognition of rare diseases as a global health challenge. The day is celebrated on the last day of February every year. This year’s Rare Disease Day is February 28, 2013. The website offers information about events being held around the country, as well as information about advocacy and becoming involved in raising awareness of rare diseases.

FDA Office of Orphan Products Development
The U.S. Food and Drug Administration works with key stakeholders, including industry, patient groups, and academia, to advance the identification and development of therapies that target rare diseases.

Orphanet is led by a European consortium of some forty countries, coordinated by the French team. National teams are responsible for the collection of information on specialized clinics, medical laboratories, ongoing research, and patient organizations in their country. The French coordinating team is responsible for the infrastructure of Orphanet, management tools, quality control, rare disease inventory, classifications, and production of the encyclopedia.

RareShare is a social networking site for anyone in the United States or Europe who suffers from an “orphan” disease.

This site is a comprehensive compendium of both open and recently completed clinical trials in the United States and around the world. See also the Health Learning Center’s pathfinder for clinical trials.


  • Clinical trials: what patients and healthy volunteers need to know. Speid L. 2010. This book includes a chapter entitled “Clinical Trials Involving Rare or Orphan Diseases.”

Contact Us

For more information, or for assistance in locating information specific to your condition, please contact the Health Learning Center at 312.926.5465 or HLC@nmh.org.

Last UpdateFebruary 15, 2013