Guide To Understanding The Different Blood Types

Other Typing Systems

The most common blood typing systems are the ABO and Rh systems. Individuals need to know their blood type according to these systems. In fact, they may only need to know these systems. However, there are other typing systems. Some of these systems are the MNS, Kell, and Lewis systems. The MNS system is based on chromosome 4 and two genes, glycophorin A and B, on it. This system contains forty-six antigens. The Kell system is a group of antigens that have an important link to autoimmune conditions, such as autoimmune hemolytic anemia. Evidence indicates that Kell antigens are important in transfusions as well.

The Lewis system of blood typing is based on the FUT3 and FUT2 genes (Lewis and Secretor genes, respectively), which are found on chromosome 19. The antigens in this system do not appear to be relevant to blood transfusions, since reports indicate that the donor's red blood cells will develop the antigens of the recipient. In fact, the risk of complications of mixing different blood types (as categorized by these other typing systems) is fairly low overall.