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Blood type (also called a blood group) is a classification of blood, based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system.
A complete blood type would describe each of the 45 blood groups, and an individual's blood type is one of many possible combinations of blood-group antigens. [3] Almost always, an individual has the same blood group for life, but very rarely an individual's blood type changes through addition or suppression of an antigen in infection, malignancy, or autoimmune disease.
The "O" blood type (usually resulting from the absence of both A and B alleles) is very common around the world, with a rate of 63% in all human populations. [135] Type "O" is the primary blood type among the Indigenous populations of the Americas, particularly within Central and South American populations, with a frequency of nearly 100%. [ 135 ]
The ABO blood group system is used to denote the presence of one, both, or neither of the A and B antigens on erythrocytes (red blood cells). [1] For human blood transfusions , it is the most important of the 44 different blood type (or group) classification systems currently recognized by the International Society of Blood Transfusions (ISBT ...
The antigens Aua and Aub, known as the Auberger antigens, were once thought to make up a separate blood group but were later shown to be Lutheran antigens arising from variations in the BCAM gene. The phenotypes Lu(a+b−) and Lu(a+b+) are found at various frequencies within populations. The Lu(a−b+) phenotype is the most common in all ...
With regard to Mozabite Berbers, one-third (33%) of Mozabite Berber mtDNAs have a Near Eastern ancestry, probably having arrived in North Africa ~50,000 years ago, and one-eighth (12.5%) have an origin in sub-Saharan Africa. Europe appears to be the source of many of the remaining sequences, with the rest (54.5%) having arisen either in Europe ...
The foremost pioneer of the study of population genetics was Luigi Luca Cavalli-Sforza.Cavalli-Sforza used classical genetic markers to analyse DNA by proxy. This method studies differences in the frequencies of particular allelic traits, namely polymorphisms from proteins found within human blood (such as the ABO blood groups, Rhesus blood antigens, HLA loci, immunoglobulins, G-6-P-D ...
The term human blood group systems is defined by the International Society of Blood Transfusion (ISBT) as systems in the human species where cell-surface antigens—in particular, those on blood cells—are "controlled at a single gene locus or by two or more very closely linked homologous genes with little or no observable recombination between them", [1] and include the common ABO and Rh ...