"Rare diseases'' may seem straightforward, affecting a small percentage of the population, although definitions of rarity differ globally. For instance, the U.S. defines these diseases as affecting fewer than 200,000 people, while the EU uses a prevalence criterion of fewer than 1 in 2,000. Additionally, rarity can be context-specific, varying across demographics and regions, emphasizing the intricate nature of these conditions.​

Are Rare Diseases Really Rare?

Rare diseases” may seem straightforward, affecting a small percentage of the population, although definitions of rarity differ globally. For instance, the U.S. defines rare diseases as affecting fewer than 200,000 people, while the EU uses a prevalence criterion of fewer than 1 in 2,000. Additionally, rarity can be context-specific, varying across demographics and regions, emphasizing the intricate nature of these conditions.