Secretor status and ABH antigens (FUT2 gene)
The ABH blood group and Lewis antigens are not only found in red blood cells, where A and B determine the group, these molecules are also present, for example, in a wide variety of tissues and can trigger susceptibility to infection, immunity, and many thromboembolic and cardiovascular diseases.
The epithelia of the gastrointestinal, respiratory, urinary, and reproductive tracts express on their surfaces carbohydrates conjugated with lipids (glycolipids) and proteins (glycoproteins) that have in their structure the ABH and Lewis antigens.
The FUT2 gene encodes for an enzyme, known as α-1,2-fucosyltransferase, which is essential for the secretion of the soluble forms of the blood group ABH and Lewis antigens in the mucosa and secretory glands. These soluble antigens produce significant physiological changes in the tissue microenvironment, affecting bacterial adherence and immunoglobulin status, among other processes.
The polymorphisms that reduce enzymatic α-1,2-fucosyltransferase activity such as W143X in Caucasians and I129F in Asians, produce the "non-secretory" phenotype that is characterized by not having these antigens in the body's secretions and, consequently, affects their susceptibility to many pathogens and diseases.
Gene or region studied