The rarest blood type in the general population is Rhnull , also known as the "golden blood" type. This blood type lacks all Rh antigens on red blood cells and is extremely rare, with fewer than 50 known cases worldwide and an estimated occurrence of about 1 in 6 million people. Rhnull blood can be donated to anyone with Rh blood types but can only be received by Rhnull individuals, making it invaluable and very difficult to obtain for transfusions
. Among the more commonly known blood types based on the ABO and Rh systems, AB negative (AB−) is the rarest, found in about 1% of the population. AB− is the rarest of the eight main blood types and is notable for being the universal plasma donor type, although its demand is relatively low compared to others
. Other rare blood types include the Bombay blood group (HH blood type), which is very rare globally but more prevalent in certain regions like India
. In summary:
- Rarest overall: Rhnull ("golden blood") - extremely rare worldwide.
- Rarest common blood type: AB negative (AB−) - about 1% of the population.
- Rare subtypes: Bombay blood group and others with rare antigen profiles.
This rarity is important for blood donation and transfusion compatibility, especially for patients requiring ongoing transfusions or with rare antigen needs
