Which gene codes for the enzyme L-fucosyltransferase?

Which gene codes for the enzyme L-fucosyltransferase?

• A. Se gene
• B. AO gene
• C. H gene
• D. KEL gene

Answer: (C)

L-fucosyltransferase is the enzyme that adds fucose to the type 2 precursor to form the H antigen on red blood cell membranes, and it is encoded by the H gene (FUT1). This H antigen serves as the foundation for the A and B antigens in the ABO system. The H gene is the RBC-specific source of this enzyme, which is why it’s the correct choice. The Se gene encodes a related fucosyltransferase (FUT2) that acts in secretions to produce soluble H antigen, not the RBC H antigen. Kell system genes, like KEL, are unrelated to H antigen biosynthesis. The AO gene is not involved in this pathway.

L-fucosyltransferase is the enzyme that adds fucose to the type 2 precursor to form the H antigen on red blood cell membranes, and it is encoded by the H gene (FUT1). This H antigen serves as the foundation for the A and B antigens in the ABO system. The H gene is the RBC-specific source of this enzyme, which is why it’s the correct choice. The Se gene encodes a related fucosyltransferase (FUT2) that acts in secretions to produce soluble H antigen, not the RBC H antigen. Kell system genes, like KEL, are unrelated to H antigen biosynthesis. The AO gene is not involved in this pathway.