Question

How does glycosylation influence the specification of blood type? The addition of N-acetylgalactosamine to the O antigen specifies type A The removal of sialic acid from the O antigen specifies type O. The removal of fructose from the O antigen specifies type B. The absence of a glycosyl unit on the O antigen specifies type O. The addition of galactose to the O antigen specifies type B The removal of N-acetylglucosamine from the O antigen specifies type A

Answer 1

The ABO blood group system was first identified by the scientist Karl Landsteiner in the year 1901. The ABO blood group system is found in human beings. This system is founded on the presence or the absence of the A as well as B antigens, which are found on the surface of the RBCs (red blood corpuscles). Based on the presence or the absence of these antigens a person can have one of the four blood groups that are O, A, AB, (or) B. RBC a-1,2,Fuc Gal-GlcNAc-Gal O-antigen B-1,3 B-1,3 a-1,2,Fuc A antigen RBC Gal-GlcNAc-Gal B-1,3 B-1.3 a-1,3 GlcNAc a-1,2 Fuc B antigen RBC Gal-GlcNAc-Gal B-1,3 B-1,3 19-1,3 Human blood group is determined by the multiple allelic system, in which i4 and i are co-dominant to each other and dominant over i°. Since the child has type O blood, his genotype should be i'i' and his mother's genotype might be 14 A (or) i4;°. For example, The O blood group carries at least one H or FUT1 gene and 2 0-genes. H-gene produces an enzyme called a-2-L fucosyltransferase under dominant condition (HH or Hh), which changes immunodominant sugar L-fucose to oligosaccharide chain on the terminal galactose and is present on the type two chains. If the H gene is defective (mutated) or present in recessive condition (hh), then it does no encode the enzyme a-2-L fucosyltransferase, and thus lack of H-substance results in the occurrence of a new phenotype called Bombay blood group. Therefore, The addition of N-acetylgalactosamine to the O antigen specifies type A. The removal of sialic acid from the O antigen specifies type 0. The removal of fructose from the O antigen specifies type B. The absence of a glycosyl unit on the O antigen specifies type 0. The addition of galactose to the antigen specifies type B. The removal of N-acetylglucosamine from the O antigen specifies type A.