A disease is considered to be “rare” when it affects between 1 in 800 and 1 in 200,000 people, depending on national guidelines.
To date, between 5,000 and 8,000 rare diseases have been identified, the majority of which are due to genetic mutation.
Each disease only of people, but when considered in their totality, 30 million Europeans are affected by rare diseases, making them a true public health issue.