| | Conditions & Treatments | Rare Diseases How rare is o negative? The O- blood type is the rarest blood group in the world. It is found in only about 6 to 7 percent of the population, and it is often in demand by hospitals. Rare Diseases - Related Articles What is the medical name for disease Lockjaw? How to Diagnose Gastrinoma Who are some famous people with Williams syndrome? What is the study of rare diseases? What is a none communicable disease? What are rare blood types? Facts on Mad Cow
