ABOSystem
The ABO system classifies human blood based on the presence or absence of A and B antigens on red blood cells and the corresponding antibodies in plasma. It was first described by Karl Landsteiner in 1901, enabling routine blood typing and safer transfusions.
The ABO gene, located on chromosome 9, encodes glycosyltransferases that modify the H antigen on red blood
The H antigen is a common precursor to A and B antigens. A minority of individuals have
Clinically, ABO compatibility is a cornerstone of transfusion medicine; transfusing ABO-incompatible blood can trigger acute hemolytic