This blood group is also known as OH or BOMBAY blood group. It is an extremely rare ABO group.
It was discovered in Bombay (now Mumbai) in India, by Dr. Y.M Bhende in 1952, In Parel`s KEM Hospital when a patient who came for treatment reacted to O blood.
According to timesofindia, less than 400 are known for having the blood group. The blood group is more likely to occur in East Indians, but, not restricted to East Indians, can also be found in Caucasians, Japanese etc.
Its also called HH group but surprisingly enough, they dont express H antigen (the antigen which is present in blood group O). The serum contains antibodies that reacted with all red blood cells` normal ABO phenotype.
As a result, they can not make antigen A or B on their red blood cells, because antigen A and B are made from H antigen.
What Is Special About People That Has Bombay Blood Group?
People with bombay blood group can donate red blood cells to any member of ABO blood group system (unless some other factors e.g Rhesus incompatibility), BUT they cannot receive blood from any other members of ABO blood group (which always contains one or more of A and B and H antigens), but only from people with Bombay blood group.
Receiving blood which contains an antigen which has never been in the patient`s own blood before is dangerous which can lead to immune reactions.
It is very important to detect bombay phenotype individuals before giving blood transfusion to avoid hemolytic transfusion reaction.