Hh blood group

The Hh blood group, also known as the Bombay phenotype, is a rare blood type first identified in 1952 by Dr. Y.M. Bhende in the city of Bombay, now known as Mumbai, India.

Discovery

Dr. Y. M. Bhende discovered the Hh blood group in Bombay (now Mumbai) in the year 1952. The nomenclature, 'Bombay phenotype', is derived from the location of its discovery.

Characteristics

The defining feature of this phenotype is the absence of ABO antigens, along with the presence of anti-A, anti-B, and anti-H antibodies in the plasma. This occurs because of a mutation in the H gene, preventing the formation of the H antigen, a precursor to the ABO antigens.

Geographic Distribution

While this blood type can be found worldwide, it has a higher frequency in the Indian subcontinent, including countries such as India, Bangladesh, and Pakistan. There is also a notable presence in some regions of the Middle East, including Iran.

Clinical Significance

In terms of medical treatments, individuals with the Bombay phenotype can only receive blood transfusions from other individuals with the same blood group due to the presence of anti-H antibodies. This presents a significant challenge given the rarity of this blood type.

Genetic Basis

The Bombay phenotype is inherited in an autosomal recessive manner. This means that both parents must carry the recessive gene for a child to express the Bombay phenotype.

See Also

• Blood type
• ABO blood group system

References

Hh blood group Resources
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