Question

What is HH blood type?

Answer 1

The presence and absence of antibodies and hereditary antigenic compounds on the surface of red blood cells are used to classify blood types. The ABO blood group system is made up of four different blood groups: A, B, AB, and O. It is based on antigens and antibodies found on red blood cells and in plasma. Antigens and antibodies are both protein molecules that are found on the surface of Red Blood Cells and in the plasma. Antigens are found on the surface of Red Blood Cells and antibodies are found in the plasma.

Complete answer:
The hh blood group, often known as Bombay Blood, is an uncommon blood genotype that was initially discovered in Mumbai (then called Bombay). Dr. Y.M. Bhende discovered it in $1952$. This blood phenotype is predominantly seen in India, Bangladesh, Pakistan, and a few Middle Eastern countries. The hh phenotype is characterised by the absence of H antigen, which is also present in the O blood group. As a result, they are unable to produce A antigen or B antigen on their red blood cells. As a result, people with the Bombay blood group can donate blood to any ABO blood group member, but they cannot receive blood from any ABO blood group member.

Additional information:
Apart from the ABO blood grouping system, there is also the Rh blood grouping system. About two-thirds of the population has the third antigen, known as Rh factor or Rh antigen, on the surface of their red blood cells, which determines whether the blood group is positive or negative. An individual is rhesus positive $\left( {Rh + ve} \right)$ if the Rh factor is present; if the $Rh$ factor is absent, the individual is rhesus negative $\left( {Rh - ve} \right)$ because they develop $Rh$ antibodies. As a result, donor-individual compatibility is
also critical in this scenario.

Note:
Individuals who have inherited two recessive strains of the H gene form the Bombay Blood group. These people don't manufacture the H carbohydrate. Because both parents have the allele, their offspring will inherit this blood type. Furthermore, the Bombay Blood has a higher likelihood of both parents and the child having the same blood type. The H antigen is a short sugar sequence found on numerous cells throughout the human body, but mainly on red blood cell membranes and floating freely in plasma and secretions.