The definition of rare disease varies across countries and jurisdictions, but it usually takes into account disease prevalence, severity and existing therapeutic options. In the United States, rare disease is defined as a disease or condition that affects fewer than 200,000 People. In the EU, disease is defined as rare when it affects fewer than 5 in 10,000 people. There are approximately 7,000 different rare diseases known today, with many more still to be identified. Rare d