Abstract:
Von Willebrand disease (vWD) is the most
comman inherited bleeding disorderr. Von Willebrand's
factor (vWF) is a glycoprotein produced by' vascular endothelium
with a molecular weight about 200000. It froms
multimers in the circrtlation2. Von Willebrand's factor
has two main functions. It stabilizes factor VIII in
circulation and promotes adhesion of platelets to damaged
vasctdar endothelium. The' gene for vWF is located
in chromosome 12 and genetic mutation of this
gene calrses vWD. There are 3 different types of vWD
Type I and II has autosomal dominant inheri-
tance pattern and type III the most severe form has an
antosomal recessive inheritance3.
Type I is the most common mildest form present
in approdmately 75o/" of patients. It is associated with
a quantitative deficiency of vWF. In type II the defect
is qualitative. In these cases often a family history of
mucocutaneous bleeding and perscnal history of
mucocutaneous bleeding tendency and menorrhagia
often occur.,Major haemorrhages are rare. Type III
disease is associated with a negligible amount of vWF
{both qrlantity and fttnction affected) and therefore a
significant reduction in factorVlll activity. In these
cases tire bleeding history is severe and can cause life
threatening haemorrhagesa.
