What are the worlds rarest diseases?
From the primitive cavemen to today’s brightest scientists, humans have always faced the many problems diseases pose. Some of these diseases are hereditary conditions passed on from parents to children; others occur as the result of random genetic mutations. Still others are the handiwork of microscopic organisms that have evolved to thrive inside the human body. Some diseases are regular occurrences throughout human populations, at times swelling to epidemic levels as they spread through large areas. Other diseases occur with far less regularity, though the exact definition of rare disease, or orphan disease, varies from country to country. The National Institute of Health classifies a rare or orphan disease as one with fewer than 200,000 cases in the country. The European Union defines it as any disease that affects five or fewer people
