Haematologica Reports 2005; 1(issue 4): 4-6 [prev][index][next]
Prevalence of von Willebrand disease in the Nordic
Region
Erik Berntorp, Páll T. Önundarson
From the Department of Coagulation Disorders, Malmö University
Hospital, Malmö, Sweden (EB);
Department of Laboratory Hematology and Hemostasis Center,
Landspitali University Hospital, Reykjavik, Iceland (PTÖ), on
behalf of the Nordic Hemophilia Council
Von Willebrand disease (VWD) encompasses a wide spectrum of
disease severity ranging from rare mild bleeding symptoms to severe
hemorrhagic episodes that are similar to those of severe
hemophilia. Due to this variation, the reported prevalence of VWD
is a reflection of the criteria by which patients are identified.
There are three subtypes of VWD. In type 1, the von Willebrand
factor (VWF) is structurally normal, but has a plasma concentration
that is subnormal, thus causing a bleeding diathesis. However, many
subjects carrying the trait may have a normal VWF level and no
increased bleeding tendency. Thus, type 1 VWD trait includes
subjects carrying the hereditary marker who are phenotypically
normal. Furthermore, levels of VWF may be low for other reasons
than mutations in the VWF gene. It follows that there is a
“grey zone” between the sick and the healthy and the
definition of VWD type 1 can frequently be
questioned.1,2 [>Read full article
in PDF]