VonWillebrand Factors

VonWillebrand factor (vWF) is a complex multimeric
protein found in plasma, platelets, and
subendothelial connective tissue. It has two
basic biological functions: it binds to specific
receptors on the surface of platelets and subendothelial
connective tissue, and it forms bridges
between platelets and damaged regions of a
vessel. Furthermore, it binds to clotting factor
VIII and stabilizes it. Deficiency of vWF leads to
decreased or absent platelet adhesion and to
secondary deficiency of factor VIII (von Willebrand
disease or von Willebrand–Jürgens syndrome).
Hereditary deficiency of vWF is the
most common bleeding disorder in man, with a
frequency of about 1:250 for all forms, including
the mild ones, and about 1:8000 for severe
forms.