Hh blood group final step in the synthesis of the molecule. Depending upon a person's ABO blood type, the H antigen is converted into either the A antigen, B antigen, or both. If a person has group O blood, the H antigen remains unmodified. Therefore, the H antigen is present more in blood type O and less in blood type AB. Two regions of the genome encode two enzymes with very similar substrate specificities: the H locus (FUT1) which encodes the Fucosyl transferase and the Se locus (FUT2) that instead indirectly encodes a soluble form of the H antigen, which is found in
Human blood group systems three types of cells: The most common type of grouping is the ABO blood group system. The varieties of glycoprotein and glycolipid coating on red blood cells divides blood into four groups: Another antigen, the Rh factor, plays an important part in the grouping of blood. If this is present, the particular blood type is called Rh-positive. If it is absent, it is called Rh-negative. In addition to the ABO and Rh blood group systems, there are more than two hundred minor blood groups that can complicate blood transfusions. These are known as rare blood types. Whereas common blood types