Rare diseases, also known as orphan diseases, are a diverse group of disorders that, despite each individual condition's rarity, collectively affect a significant portion of the global population. The exact definition of a rare disease varies from country to country, but generally, a disease is considered rare when it affects a limited number of people within a specific region or population. The World Health Organization (WHO) defines a rare disease as one that strikes fewer than 65 per 100,000 people. According to the National Organization of Rare Disorders of the USA, 2 a rare disorder is a disease or condition that affects fewer than 200,000 Americans (i.e., less than ~60 per 100,000). In the European Union, a rare disease is one that affects no more than 1 person in 2000 (i.e., <50 per 100,000). According to Global Genes, a global non-profit advocacy organization for individuals fighting rare and genetic diseases , currently approximately 10,000 rare diseases exist globally, with new ones being continually discovered. About 80% of these diseases have been identified as of genetic origins , and they often manifest in diverse and unpredictable ways.