XK (protein)


XK is a protein found on human red [blood cells] and other tissues which is responsible for the Kx antigen which helps determine a person's blood type.

Clinical significance

The Kx antigen plays a role in matching blood for blood transfusions.
Mutation of XK protein may lead to McLeod syndrome, a multi-system disorder characterized by hemolytic anemia, myopathy, acanthocytosis, and chorea.
XK is located on the X chromosome and absence of the XK protein is an X-linked disease.

Clinical diagnostic

Clinical testing in patient care for Kx antigen follows published minimum quality and operational requirements, similar to red cell genotyping for any of the other recognized blood group systems. Molecular analysis can identify gene variants that may affect Kx antigen expression on the red cell membrane.

Function

XK is a membrane transport protein of unknown action.