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The Colton antigen system (Co) is present on the membranes of
red blood cells Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...
and in the tubules of the
kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...
and helps determine a person's
blood type A blood type (also known as 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 ...
. The Co
antigen In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune respon ...
is found on a protein called aquaporin-1 which is responsible for water
homeostasis In biology, homeostasis (British also homoeostasis) (/hɒmɪə(ʊ)ˈsteɪsɪs/) is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and i ...
and urine concentration. The Co antigen is important in
transfusion medicine Transfusion medicine (or transfusiology) is the branch of medicine that encompasses all aspects of the transfusion of blood and blood components including aspects related to hemovigilance. It includes issues of blood donation, immunohematology ...
. 99.8% of people possess the Co(a)
allele An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chro ...
. Individuals with Co(b) allele or who are missing the Colton antigen are at risk for a
transfusion reaction Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but mod ...
such as
hemolytic anemia Hemolytic anemia or haemolytic anaemia is a form of anemia due to hemolysis, the abnormal breakdown of red blood cells (RBCs), either in the blood vessels (intravascular hemolysis) or elsewhere in the human body (extravascular). This most commonl ...
or
alloimmunization Alloimmunity (sometimes called isoimmunity) is an immune response to nonself antigens from members of the same species, which are called alloantigens or isoantigens. Two major types of alloantigens are blood group antigens and histocompatibility an ...
. Antibodies against the Colton antigen may also cause
hemolytic disease of the newborn Hemolytic disease of the newborn, also known as hemolytic disease of the fetus and newborn, HDN, HDFN, or erythroblastosis foetalis, is an alloimmune condition that develops in a fetus at or around birth, when the IgG molecules (one of the fiv ...
, in which a pregnant woman's body creates antibodies against the blood of her fetus, leading to destruction of the fetal blood cells.Covin RB, Evans KS, Olshock R, Thompson HW. ''Acute hemolytic transfusion reaction caused by anti-Coa.'' Immunohematol. 2001 Jun;17(2):45-9.


References

* OMIM entry for the Colton antigen


External links


Colton
at
BGMUT The BGMUT (Blood Group antigen gene MUTation) Database documents allelic variations in the genes encoding for human blood group systems. It was set up in 1999 through an initiative of the Human Genome Variation Society ( HGVS). Since 2006, it has ...
Blood Group Antigen Gene Mutation Database at NCBI,
NIH The National Institutes of Health, commonly referred to as NIH (with each letter pronounced individually), is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late 1 ...
Blood antigen systems Transfusion medicine Genes on human chromosome 7 {{Gene-7-stub