The European Union defines a disease or condition as rare if it affects fewer than 1 in 2,000 (1) people within the general population. Currently, there are over 6,000 (2) known rare diseases and new conditions are being described through medical literature on a regular basis.
1 in 17 people* will be affected by a rare disease at some point in their lives. This amounts to 3.5 million people in the UK* and 30 million people across Europe (1).
The majority of rare diseases currently have no effective treatment (1).
8 out of 10 rare diseases 3 have a genetic cause and 99% of genetic conditions are classed as rare (4). Often rare diseases are chronic and life-threatening. Rare diseases can be single gene, multifactorial, chromosomal or non-genetic.
On average, it takes over four years (5) to receive an accurate diagnosis of a rare disease.
Rare diseases include rare cancers such as childhood cancers and some other well known conditions, such as cystic fibrosis and Huntington’s disease.
If you would like more information on specific rare diseases, please visit Orphanet, the portal for rare diseases and orphan drugs, or check out the supporters of the Rare Disease UK campaign for relevant patient organisations.
Nguengang Wakap, S., Lambert, D.M., Olry, A. et al. Estimating cumulative point prevalence of rare diseases: analysis of the Orphanet database. Eur J Hum Genet 28, 165–173 (2020). https://doi.org/10.1038/s41431-019-0508-0