Rare diseases are denoted as such based on their prevalence—the specific rate at which they are considered rare depends on where you live. For example, according to the Rare Disease Day website, in Europe, a rare disease or disorder will affect fewer than 1 in 2,000 people. In the US, that same disease or disorder would be considered rare if it affects fewer than 0.01% of the population—or fewer than 200.000 Americans. [1]

There are over 6000 existing rare diseases, 80% of which have identified genetic links. [1] The othe