The Indian blood group system (In) is a classification of
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...
based on the presence or absence of
inherited 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 respons ...
s that reside within the
CD44
The CD44 antigen is a cell-surface glycoprotein involved in cell–cell interactions, cell adhesion and migration. In humans, the CD44 antigen is encoded by the ''CD44'' gene on chromosome 11. CD44 has been referred to as HCAM (homing cell adhes ...
molecule that is expressed on the surface of
blood cell
A blood cell, also called a hematopoietic cell, hemocyte, or hematocyte, is a cell produced through hematopoiesis and found mainly in the blood. Major types of blood cells include red blood cells (erythrocytes), white blood cells (leukocytes) ...
s.
It is named so because 4% of the population in India possess it.
Most individuals express the In
b antigen that results from an
arginine residue at position 46 of CD44 . The In
a blood type results from a substitution
proline for arginine at this same position.
References
Blood antigen systems
Transfusion medicine
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