# Von Willebrand’s Disease
Symptoms: bleeding tendencies e.g. frequent nosebleeds, bleeding gums, and heavy menses (menorrhagia) in women.
“A normal PT and PTT indicate that the clotting cascade is intact, unless there is a mild factor deficiency. In such cases, further evaluation should focus on platelet function activity to evaluate for a platelet disorder, the most common of which is von Willebrand disease.” AAFP 2016
Von Willebrand disease is the most common congenital bleeding disorder. It is also the most common inherited bleeding disorder.
It is autosomal dominant.
It is caused by an abnormality in von Willebrand factor (vWF). vWf is the carrier protein for factor VIII and is also a cofactor in platelet adhesion. As a result, patients with von Willebrand disease will have an abnormal bleeding time and often a prolonged partial thromboplastin time (PTT) with a normal prothrombin time (PT) and INR. Patients with Von Willebrand’s disease will also have a normal platelet count and morphology.
Treatment: Desmopressin (DDAVP). Desmopressin 0.3 μg/kg (max dose, 20 μg) SQ or IV every 12 hours for a total of 3-4 doses.
“Von Willebrand disease (vWD) is a common coagulation disorder generally due to a hereditary reduction in the quality or quantity of a protein complex required for platelet adhesion, known as von Willebrand factor (vWF). The extent of deficiency varies greatly, resulting in vWD subtypes ranging from asymptomatic to serious. A common problem associated with vWD is menorrhagia, and the diagnosis should always be entertained in women who experience excessive menstrual blood loss. Although tests measuring vWF are easily obtained, interpretation of the results can be challenging since vWF levels can be affected by blood type, inflammation, infection, trauma, and emotional stress. Confirmation of vWD often requires the expertise of a hematologist. Although the results for all laboratory tests listed can fall within their reference ranges in a patient with vWD, the finding most suggestive of this diagnosis is an isolated prolonged partial thromboplastin time” ABFM
Reference
Am Fam Physician. 2016 Feb 15;93(4):279-286. http://www.aafp.org/afp/2016/0215/p279.html