The Scianna blood antigen system consists of seven
antigens
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 response. ...
.
These include two high frequency antigens Sc1 and Sc3, and two low frequency antigens Sc2 and Sc4.
The very rare null
phenotype
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological prop ...
is characterised by the absence of Sc1, Sc2 and Sc3.
The antigens are caused by changes in the
erythroid
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 ...
membrane associated
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...
(
ERMAP
Erythroid membrane-associated protein is a protein that in humans is responsible for the Scianna antigen system, Scianna blood group system, and is encoded by the ''ERMAP'' gene.
References
Further reading
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External li ...
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History
This blood group system was discovered in 1962 when a high frequency antigen was detected in a young woman (Ms. Scianna) who had experienced several late pregnancy losses due to
haemolytic disease of the fetus.
References
{{Transfusion medicine
Antigens
Blood
Cell biology