A blood type is a description an individual's characteristics of red blood cells due to substances (carbohydrates and proteins) on the cell membrane. The two most important classifications to describe blood types in humans are ABO and Rh factor. There are 46 other known antigens, most of which are much rarer than ABO and Rh. Blood transfusions from incompatible groups can cause an immunological transfusion reaction, resulting in hemolytic anemia, renal failure, shock, and death. Human red blood cells Red blood cells are the most common type of blood cell and are the vertebrate bodys principal means of delivering oxygen to body tissues via the blood. ... Carbohydrates (literally hydrates of carbon) are chemical compounds that act as the primary biological means of storing or consuming energy, other forms being fat and protein. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... An antigen is any molecule that is recognized by antibodies. ... Hemolysis (alternative spelling haemolysis) is the excessive breakdown of red blood cells. ... Renal failure is when the kidneys fail to function properly. ... This article is about medicine. ...

ABO

Humans have the following blood types along with their respective antigens and antibodies: An antigen is any molecule that is recognized by antibodies. ... Schematic of antibody binding to an antigen An antibody is a protein used by the immune system to identify and neutralize foreign objects like bacteria and viruses. ...

• Individuals with type A blood have red blood cells with antigen A on their surface and produce antibodies against antigen B in their blood serum. Using the blood compatibility chart below, for example, an A-negative person can only receive blood from another A-negative person or from an O-negative person.
• Individuals with type B blood have the opposite arrangement, antigen B on the cell and produce antibodies to substance A in their serum.
• Type AB people have red blood cells with both antigens A and B, and do not produce antibodies against either substance in their serum. Therefore, a person with type AB blood can safely receive any ABO type blood and is called a "universal receiver", but cannot donate blood except to the corresponding AB type people shown in the blood compatibility table below.
• Type O people have red blood cells with neither antigen, but produce antibodies against both types of antigens. Because of this arrangement, type O can be safely given to any person with any ABO blood type. Hence, a person with type O blood is said to be a "universal donor" but can only receive blood from the corresponding O type people shown in the blood compatibility table below. Thus, for example, an O-negative person can only receive blood from another O-negative person.

Overall, the O blood type is the most common blood type in the world, although in some areas, such as Norway, the A group dominates. The A antigen is overall more common than the B antigen. Since the AB blood type requires the presence of both A and B antigens, the AB blood type is the rarest of the ABO blood types. There are known racial and geographic distributions of the ABO blood types [1] (http://anthro.palomar.edu/vary/vary_3.htm). Norway - Wikipedia /**/ @import /skins/monobook/IE50Fixes. ...

The precise reason why people are born with antibodies against an antigen they have never been exposed to is unknown. It is believed that some bacterial antigens are similar enough to the A and B glycoproteins, and that antibodies created against the bacteria will react to ABO-incompatible blood cells. Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus_Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... A glycoprotein is a macromolecule composed of a protein and a carbohydrate (a sugar). ...

Apart from on red blood cells, the ABO antigen is also expressed on the glycoprotein von Willebrand factor (vWF), which participates in hemostasis (control of bleeding). In fact, blood type O predisposes very slightly to bleeding, as vWF is degraded more rapidly. A glycoprotein is a macromolecule composed of a protein and a carbohydrate (a sugar). ... Von Willebrand factor (vWF, also called Factor VIII-related antigen) is a blood protein of the coagulation system. ... Hemostasisis the physiologic process which results in the cessation of bleeding in most animals with a closed circulatory system. ...

Austrian scientist Karl Landsteiner was awarded the Nobel Prize in Physiology or Medicine in 1930 for his work in discovering ABO blood types. Karl Landsteiner (June 14, 1868 - June 26, 1943), was an Austrian biologist. ... List of Nobel Prize laureates in Physiology or Medicine from 1901 to the present day. ... 1930 is a common year starting on Wednesday. ...

Rhesus

Another characteristic of blood is Rhesus factor or Rh factor. It is named after the Rhesus Monkey, where the factor was first identified in 1940. Someone either has or does not have the Rh factor on the surface of their red blood cells. This is indicated as + or -. This is often combined with the ABO type. Type O+ blood is most common, though in some areas type A prevails, and there are other areas in which as many as 80 percent of the people are type B. Binomial name Macaca mulatta Zimmermann, 1780 The Rhesus Macaque (Macaca mulatta), often called the Rhesus monkey, is one of the best known species of Old World monkeys. ...

Matching the Rhesus factor in the ABO system is very important, as mismatching (an Rh positive donor to an Rh negative recipient) will cause hemolysis. The converse is not true: Rh+ patients do not react to Rh- blood. Hemolysis (alternative spelling haemolysis) is the excessive breakdown of red blood cells. ...

Rh disease occurs when an Rh negative mother who has already had an Rh positive child (or an accidental Rh+ blood transfusion) carries another Rh positive child. After the first pregnancy, the mother develops antibodies against Rh+ red blood cells, which cross the placenta and hemolyses the blood of the second child. This reaction doesn't always occur and is less likely to occur if the child carries either the A or B antigen and the mother does not. In the past, Rh incompatibility could result in stillbirth or death of the mother. Rh incompatibility was until recently the most common cause of long term disability in the United States. At first, this was treated by transfusing the blood of infants who survived. At present, it can be treated with certain anti-Rh(+) antisera, the most common of which is Rhogam (anti-D). It can be anticipated by determining the blood type of every child of a RhD- mother; if it is Rh+, the mother is treated with anti-D to prevent development of antibodies against Rh+ red blood cells. Rh disease (also Rhesus disease or Morbus haemolyticus neonatorum) is a condition that occurs when an Rh negative mother has given birth to an Rh positive baby and subsequently becomes pregnant with an Rh positive child. ... The placenta is an ephemeral (temporary) organ present only in female placental mammals during gestation (pregnancy). ... Hemolysis (alternative spelling haemolysis) is the excessive breakdown of red blood cells. ... Rhogam: Rh0 immunoglobulin, also called anti-Rh or anti-D immunoglobulin is an injectable blood product used to protect an Rh-positive fetus from antibodies by its Rh-negative mother. ...

Inheritance

ABO

Blood groups are inherited from both parents. The ABO blood type is controlled by a single gene with three alleles: i, A, and B. The gene encodes a glycosyltransferase, an enzyme that modifies the carbohydrate content of the red blood cell antigens. The gene is located on the long arm of the ninth chromosome (9q34). This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... An allele is any one of a number of alternative forms of the same gene occupying a given locus (position) on a chromosome. ... Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ... Carbohydrates (literally hydrates of carbon) are chemical compounds that act as the primary biological means of storing or consuming energy, other forms being fat and protein. ... Human red blood cells Red blood cells are the most common type of blood cell and are the vertebrate bodys principal means of delivering oxygen to body tissues via the blood. ... Figure 1: Chromosome. ...

A allele gives type A, B gives type B, and i gives type O. A and B are dominant over i, so ii people have type O, AA or Ai have A, BB or Bi have type B. AB people have both phenotypes because A and B express a special dominance relationship: codominance. Thus, it is usually impossible for a type AB parent to have a type O child (it is, however, no direct proof of illegitimacy). Co-dominance and the closely related incomplete dominance are terms in genetics that refer to the situation where an organism inherits a combined or blended phenotype instead of just the dominant trait, when two different alleles are present in the genotype. ... Illegitimacy was a term in common usage for the condition of being born of parents who are not validly married to one another; the legal term is bastardy. ...

Evolutionary biologists theorize that the A allele evolved earliest, followed by O and then B. This chronology accounts for the percentage of people worldwide with each blood type. It is consistent with the accepted patterns of early population movements and varying prevalent blood types in different parts of the world. (For instance, B is very common in populations of Asian descent, but rare in ones of European descent.) The term Asian can refer to something or someone from Asia. ... This article is about the continent. ...

Rhesus

Rh (or the D antigen) is inherited on one locus (on the short arm of the first chromosome, 1p36.2-p34) with two alleles, of which Rh+ is dominant and Rh- recessive. The gene codes for a polypeptide on the red cell membrane. Rh- individuals (dd genotype) do not produce this antigen, and may be sensitized to Rh+ blood. Peptides are the family of molecules formed from the linking, in a defined order, of various amino acids. ...

Two very similar epitopes, Cc and Ee, appear to be closely related to Rh.

Rare phenotypes

Bombay phenotype

The rare individuals with Bombay phenotype do not express substance H on their red blood cells and therefore do not bind A or B antigens. Instead, they produce antibodies to H substance (which is present on all red cells except those of hh phenotype) as well as to both A and B antigens and are therefore compatible only with other hh donors. The phenotype of an individual organism is either its total physical appearance and constitution, or a specific manifestation of a trait, such as size or eye color, that varies between individuals. ...

Individuals with Bombay phenotype blood groups can only be transfused with blood from other Bombay phenotype individuals. Given that this condition is very rare to begin with, any person with this blood group, who needs an urgent blood transfusion, may be simply out of luck, as it would be quite unlikely that any blood bank would have any in stock.

Patients who test as type O may have the Bombay phenotype: they have inherited two recessive alleles of the H gene, (their blood group is O_h and their genotype is "hh"), and so do not produce the "H" protein that is the precursor to the "A" and "B" antigens. It then no longer matters whether the A or B enzymes are present or not, as no A or B antigen can be produced since the precursor antigen is not present. In genetics, the term recessive gene refers to an allele that causes a phenotype (visible or detectable characteristic) that is only seen in a homozygous genotype (an organism that has two copies of the same allele). ...

Despite the designation O, O_h -ve is not a sub-group of any other group, not even O -ve or O +ve. When this Blood group was first encountered, it was found not to be of either group A or B and so was thought to be of Group O. But on further test, it did not match even for O-ve or O+ve because of the absence of Antigen 'h'. The H antigen is a precursor to the A and B antigens. For instance, the B allele must be present to produce the B enzyme that modifies the H antigen to become the B antigen. It is the same for the A allele. However, if only recessive alleles for the H antigen are inherited (hh), as in the case above, the H antigen will not be produced. Subsequently, the A and B antigens also will not be produced. The result is an O phenotype by default since a lack of A and B antigens is the O type. The name "Bombay group" originates from the city of Bombay, now known as Mumbai, in India. The blood phenotype was first discovered in Bombay. This article or section should be merged with Mumbai (Bombay) This article is about the city formerly known as Bombay. ... The Republic of India is the second most populous country in the world, with a population of more than one billion, and is the seventh largest country by geographical area. ...

Compatibility

Blood donors and blood recipients must have compatible blood types. O- is the universally compatible blood type. The chart below illustrates how people with different blood types can receive or donate other blood (X means compatible). An A- person, for example, can receive either O- or A-, and can donate to people with AB+, AB-, A+ or A- blood.

In general, people with type O Rh- are referred to as universal donors, as their blood can be transfused to anyone in need. It is thus the most highly sought after blood type in blood banks and hospitals. A type AB Rh+ is referred to as a universal receiver because he or she can receive blood of any type.

Frequency

Blood types are not evenly distributed throughout the human population. O+ is the most common, AB- is the rarest. There are also variations in blood-type distribution within human subpopulations.

Other blood types

Other blood type systems exist to describe the presence or absence of other antigens. Many are named after the patients in whom they were initially encountered.

• Diego positive blood is found only among East Asians and Native Americans.
• MNS systems gives blood types of M, N, and MN. It has use in tests of maternity or paternity.
• Duffy negative blood gives partial immunity to malaria.
• The Lutheran system describes a set of 21 antigens.
• Other systems include Colton, Kell, Kidd, Lewis, Landsteiner-Wiener, P, Yt or Cartwright, XG, Scianna, Dombrock, Chido/Rodgers, Kx, Gerbich, Cromer, Knops, Indian, Ok, Raph, and JMH.

East Asia is a subregion of Asia. ... Native Americans (also Indians, Aboriginal Peoples, American Indians, First Nations, Alaskan Natives, Amerindians, or Indigenous Peoples of America) are the indigenous inhabitants of The Americas prior to the European colonization, and their modern descendants. ... Red blood cell infected with Malaria (Italian: bad air; formerly called ague or marsh fever in English) is an infectious disease which causes about 500 million infections and 2 million deaths annually, mainly in the tropics and sub-Saharan Africa. ...

Social significance

In Japan (and to a certain extent in Taiwan) a popular belief is that personality is related to blood type. Visitors to the country are often surprised to be asked their blood type by people they encounter. Japanese people are also often surprised when foreigners say that they do not know their own blood type. Whilst many Japanese people understand that blood typing doesn't hold any social significance in Western societies, others may conclude that the visitor is too "ashamed" of their blood type to reveal it to others. Furthermore, from the preponderance of some blood types in a population, Japanese "experts" claim to be able to deduce the character of that population. The experts also believe that they can calculate how well the blood types of different people match, a Japanese employer could therefore aim to get a proper mix of blood types among their personnel.

Some nationalisms such as the Basque one have used the different proportion of blood types in different regions or populations as a mark of different race. This article is about the Basque people. ... Human beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. ...

In the United States, few African Americans donate blood, resulting in a shortage of U-negative and Duffy-negative blood for African American patients.

References

• Landsteiner K. Zur Kenntnis der antifermentativen, lytischen und agglutinierenden Wirkungen des Blutserums und der Lymphe. Zentralblatt Bakteriologie 1900;27:357-62.

External links

• Racial & Ethnic Distribution of ABO Blood Types (http://www.bloodbook.com/world-abo.html) - bloodbook.com
• OMIM 110300 (http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=110300) (ABO) and OMIM 111680 (http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=111680) (Rh/D)
• Red Cross Blood Information (http://www.redcrossblood.com/blood_information.htm)