The H Blood Groups refer to a system of blood group antigens that are present on the surface of red blood cells. These antigens are encoded by the H gene, also known as the FUT1 gene, located on chromosome 19. The H antigens are essential for the proper formation of other blood group antigens called A and B antigens.
Individuals with H blood groups can be classified into three main types: H+, H-, and oh (Bombay phenotype). H+ individuals possess the H antigen and are the most common blood type in the general population. H- individuals lack the H antigen due to a mutation in the FUT1 gene.
The H antigen acts as a precursor for the formation of A and B antigens. In individuals with the A blood group, the H antigen is further modified by the addition of N-acetyl-galactosamine to produce the A antigen. In individuals with the B blood group, the H antigen is modified by the addition of galactose to produce the B antigen.
The Bombay phenotype, or oh blood group, is a rare condition in which individuals completely lack the H antigen. As a result, they are unable to produce the A or B antigens. Individuals with the Bombay phenotype can only receive blood from other individuals with the same phenotype, making their blood extremely rare and valuable for transfusion purposes.
The H Blood Groups play a vital role in blood compatibility, transfusion medicine, and genetics, as they determine the blood type of an individual and influence their eligibility to donate or receive blood during medical procedures.
