A rare disease is one that affects less than 5 in 10,000 of the general population, as defined by the European Union. There are between 6,000 and 8,000 known rare diseases and 1 in 17 people, or 7% of the population, will be affected by a rare disease at some point in their lives. Often these rare diseases are chronic and life-threatening.
In the UK, a single rare disease may affect up to about 30,000 people. However, the vast majority of rare diseases will affect far fewer than this; some will affect only a handful or even a single person in the whole of the UK. Collectively, rare diseases affect approximately 3.5 million people in the UK and 30 million people across Europe.
The vast majority of rare diseases have a genetic component and can be caused by changes in a single gene, multiple genes or changes at the chromosomal level.
Rare diseases affect mostly children with a third of rare disease patients dying before their fifth birthday.
Rare diseases include rare cancers, such as childhood cancers, and some other well-known conditions such as cystic fibrosis and Huntington’s disease.
To know more about Genetic Alliance UK’s work on rare diseases, please check our Rare Disease UK campaign.
You can find also find more information here: Orphanet, the portal for rare diseases and orphan drugs.