Summary
A rare disease is one that affects fewer than 200,000 people in the United States. There are nearly 7,000 rare diseases. More than 25 million Americans have one.
Rare diseases:
- May involve chronic illness, disability, and often premature death
- Often have no treatment or not very effective treatment
- Are frequently not diagnosed correctly
- Are often very complex
- Are often caused by changes in genes
It can be hard to find a specialist who knows how to treat your rare disease. Disease advocacy groups, rare disease organizations, and genetics clinics may help you to find one.
NIH: National Institutes of Health
Learn More
- All about the Human Genome Project (HGP) (National Human Genome Research Institute)
- Frequently Asked Questions about Rare Diseases (National Human Genome Research Institute) Also in Spanish
- Genetic and Rare Diseases Information Center
- Genetics: MedlinePlus Genetics (National Library of Medicine) Also in Spanish
- Learning about an Undiagosed Condition in a Child (National Human Genome Research Institute)
- Learning about an Undiagosed Condition in an Adult (National Human Genome Research Institute)
- Rare Diseases at FDA (Food and Drug Administration)
Clinical Trials
- ClinicalTrials.gov: Rare Diseases (National Institutes of Health)
Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)
Find an Expert
- Contact Us (Genetic and Rare Diseases Information Center)