Bombay Blood Group (HH Blood Group) – A Rare Blood Type
Discovery and Origin
- First discovered in Mumbai (Bombay), India, in 1952 by Dr. Y.M. Bhende.
- Extremely rare, found in 1 in a million people worldwide, but more common in India (1 in 10,000 people) due to consanguineous marriages.
Unique Characteristics
- Individuals with this blood group lack the H antigen, which is the precursor for the A and B antigens in the ABO blood system.
- Contains anti-A, anti-B, and anti-H antibodies, making it incompatible with all ABO blood types.
- Can only receive blood from another Bombay blood group donor.
Clinical Significance
- Blood Transfusion Challenge: People with this blood group cannot receive O, A, B, or AB blood, as even O blood contains the H antigen.
- Rare Donor Availability: Since the blood group is rare, finding a matching donor for transfusions is difficult.
- High Risk in Emergencies: Requires special blood banking and donor registration to facilitate emergency transfusions.
Inheritance and Genetics
- Inherited as an autosomal recessive trait (both parents must carry the defective gene).
- Found mainly in South Asia, Middle East, and some parts of South America.
Diagnosis and Detection
- Standard Blood Typing Mistake: Regular ABO blood typing may classify it as O group unless specifically tested for the H antigen.
- Confirmed by:
- Anti-H Lectin Test (Ulex Europaeus test) – Differentiates Bombay group from O blood.
- Genetic Testing for mutations in the FUT1 gene.
Importance of Awareness
- Blood banks maintain separate Bombay blood group donor registries.
- Raising awareness helps in quick donor matching and life-saving transfusions.
