what's the rarest blood type

The rarest blood type in the world is the Rh-null blood type, also known as the "golden blood." It is incredibly rare, with fewer than 50 known individuals worldwide, and it lacks all Rh antigens on red blood cells. This blood type is extremely valuable for transfusions but very difficult to find donors for because it can only be given to people with Rh-null blood, and those with Rh-null blood can only receive it from others with the same type. Other rare blood types include AB-negative, the rarest of the common eight blood types, and the Bombay or HH blood type, which is also very rare but more common than Rh-null.