Someone's blood group is the type of blood that they have in their body. There are four main types: A, B, AB, and O. = blood type. Any of several immunologically distinct, genetically determined classes of human blood that are based on the presence or absence of certain antigens and are clinically identified by characteristic agglutination reactions. Also called blood type. one of the classes into which human blood can be separated, including A, B, AB and O American Equivalent: blood type
Classification of human blood according to whether red blood cells (erythrocytes) have or lack the inherited antigens called A (including A1 and A2) and B on their surface. Blood can be type O (lacking both), type A (having only A), type B (having only B), or type AB (having both). The ABO antigens make certain blood types incompatible for transfusion. They are developed well before birth and remain through life. The frequencies of blood groups vary among different racial groups and in different geographic areas. Certain diseases are rarer in persons with particular blood groups
{i} blood group that consists chiefly of the antigens fy(a) and fy(b) determined by allelic genes (named after Richard Duffy who was a hemophiliac patient)
System for classifying blood according to presence or absence of the Rh antigen (factor) in erythrocytes. Rh-negative persons who receive Rh-positive blood transfusions produce antibodies to Rh factor, which attack red blood cells with the factor if they are ever received again, causing serious illness and sometimes death. The antibodies also attack the red cells of an Rh-positive fetus carried by an Rh-negative woman if she has had a previous Rh-positive transfusion or pregnancy (see erythroblastosis fetalis). The Rh-negative trait is rare worldwide but more common in some ethnic groups. See also blood typing