Brain Sharpenerzz

The rarest blood group in the world is known as Rhnull, often called "golden blood." This blood type is unique because it completely lacks all Rh antigens on the surface of red blood cells, a feature that distinguishes it from all other blood types. While the familiar ABO system (A, B, AB, O) and the Rh factor (positive or negative) cover most people, Rhnull is extraordinarily rare—fewer than 50 people worldwide are known to have it. Rhnull was first discovered in 1961 in an Aboriginal Australian woman. The absence of Rh antigens makes this blood type extremely valuable for transfusions to people with rare blood groups, as it can be accepted by almost anyone with a compatible ABO type. However, people with Rhnull blood can only receive transfusions from other Rhnull donors, making emergencies especially challenging. For comparison, among the standard blood types, AB negative is the rarest, found in just about 1% of the population. Other rare types include the Bombay (hh) ph...