Welcome to this presentation on the biology and pathobiology of von Willebrand factor.
I'm David Lillicrap from the Department of Pathology and
Molecular Medicine at Queen's University in Kingston, Canada.
This is a picture of Dr. Erich von Willebrand,
a Finnish physician who practiced in the early part of the 20th century.
In 1926, Dr. von Willebrand described, for the first time,
the clinical features of a novel inherited bleeding disorder.
This condition now bears his name as 'von Willebrand disease'.
Dr. von Willebrand's initial observations were made in a group of
patients who resided in the Aland Islands in the Baltic Sea, shown on this slide.
In the middle group of islands,
you can see that the frequency of
von Willebrand disease was greater than 10 percent of the population.
It was amongst this group of patients that Dr. von Willebrand described a young girl who, in one of her first menstrual periods,
bled to death from severe and unrelenting menorrhagia.
Dr. von Willebrand's clinical observations in this initial group of patients
continue to form the keystone of the diagnosis of von Willebrand disease.
These patients present with a personal history of excessive mucocutaneous bleeding.
Patients with this condition often have easy, recurrent, and large bruising.
They will have episodes of prolonged and recurrent epistaxes,
and women with the condition will often be diagnosed with menorrhagia.
Bleeding from minor wounds is often persistent, and bleeding following
surgical and dental procedures is also prolonged and excessive.
Outside of the severe form of the disease
(that is, type 3 von Willebrand disease),
bleeding into joints, muscles,
and soft tissues appears to be exceedingly rare.
The relative risk (or odds ratio) for a number of