As the demand for a unique blood type known as Bombay blood group rises, it’s important to understand its individuality and the challenges faced by those that carry this rare blood type. Unlike the well-known blood groups A, B, AB, and O, determined under the ABO blood group system by the presence of antigens over red blood cells, the Bombay blood group, or hh, does not express the H antigen.
Understanding ABO Blood Group System
The classification of blood groups under the ABO system is based on the antigens found on the surface of red blood cells. For example, the AB blood group consists of both A and B antigens, while blood group A and B contain only their respective antigens. Interestingly, blood group O does not carry either A or B antigens. These groups were first identified by Austrian immunologist Karl Landsteiner in 1901.
Uniqueness of Bombay Blood Group
The Bombay blood group differs from the other categories because it does not express the H antigen that is found on the red blood cells of the A, B, AB, and O blood groups. This absence often leads to confusion between the O blood group and the Bombay blood group. However, the key distinction lies in the presence (O group) or absence (hh group) of the H antigen. The Bombay blood group was first discovered in the Indian city of Mumbai (formerly Bombay) by Dr. Y M Bhende in 1952.
The Rarity and Global Distribution of Bombay Blood Group
Categorized as a rarity, the Bombay blood group occurs globally at an incidence rate of one in four million. However, this blood type is notably more common in South Asia, specifically due to the prevalence of close community marriages and inbreeding. In India, approximately one person in 7,600 to 10,000 are born with this blood type.
Blood Transfusion Challenges for Bombay Blood Group
Individuals carrying the Bombay blood group face significant issues when they require a blood transfusion. The scarcity of the hh blood type often leads to life-threatening situations due to its non-availability. Individuals from the Bombay blood group can only receive blood transfusions from those of the same hh phenotype, eliminating the possibility of receiving from the A, B, AB, or O blood groups. If they receive blood from these groups, their bodies may reject it. However, hh blood group carriers can donate their blood to all ABO blood types.
| Blood Group | Antigen Present |
|---|---|
| A | Antigen A |
| B | Antigen B |
| AB | Antigens A and B |
| O | No A or B Antigens |
| Bombay (hh) | No Antigen H |
Storage Issues of Bombay Blood Type
Considering its rarity and the brief shelf life of blood (35-42 days), the Bombay blood group is usually not stored in blood banks. This absence further complicates the process of finding compatible donors for individuals with this blood type when the need arises.
