Von Willebrand syndrome (VWS)

What is Von Willebrand syndrome?

Von Willebrand syndrome is caused by a reduction or defect in the von Willebrand factor, a large blood protein that has numerous functions in the process of hemostasis and therefore plays an important role.

Von Willebrand syndrome is divided into 3 main types: in type 1, mild von Willebrand syndrome, von Willebrand factor is moderately reduced and functionally intact, whereas in type 3, the very rare severe von Willebrand syndrome, it is practically completely absent. Type 2, which is subdivided into subtypes 2A, 2B, 2M and 2N, describes certain qualitative and structural defects of the von Willebrand factor that impair its function.

Causes and risk factors - Von Willebrand syndrome

Von Willebrand syndrome can be hereditary and congenital – and then, unlike haemophilia, affect both men and women – but it can also be non-hereditary (acquired) due to various underlying diseases, such as autoimmune diseases, heart valve defects or so-called myeloproliferative neoplasms – if such an underlying disease is successfully treated, the acquired von Willebrand syndrome also regresses.

Willebrand syndrome: Autosomal dominant and recessive inheritance

Autosomes are chromosomes that do not belong to the sex chromosomes. In the case of autosomal inheritance, the gene is therefore located on an autosome and not on an X or Y chromosome. The autosomal dominant form is the more common variant of VWS, which means that one parent has the disease and passes it on to the child with a 50 percent probability. In autosomal recessive inheritance, the child receives an altered gene variant from both parents. In relation to the VWS types, this means:

• Type 1 – mild variant, autosomal dominant inheritance
• Type 2 – mild to moderate severity, autosomal dominant or autosomal recessive depending on the genetic defect
• Type 3 – rare, severe symptoms, autosomal recessive

Symptoms: Von Willebrand syndrome

Von Willebrand syndrome is characterized by bleeding on the skin and mucous membranes, for example nosebleeds, conspicuously heavy menstrual bleeding, bruising on the skin or prolonged bleeding after minor injuries. Severe bleeding, for example in joints or muscles, is most likely to occur in severe von Willebrand syndrome, type 3. However, serious bleeding can also occur in mild von Willebrand syndrome if the procedure is not carefully prepared with suitable bleeding prevention measures. Standardized questionnaires are used in the coagulation consultation to record and quantify the bleeding tendency.

Von Willebrand syndrome - diagnosis with us

If von Willebrand syndrome is suspected, the investigation can be complex and require several blood samples and highly specialized examinations. This is also due to the fact that the von Willebrand factor reacts as a so-called acute phase protein and can be temporarily higher during inflammation, pregnancy and numerous other influences. If the blood sample is then taken, von Willebrand syndrome can be overlooked. The tests used measure the plasma concentration and the various functions of von Willebrand factor. If necessary, special diagnostics can also be carried out in collaboration with other university hospitals (e.g. so-called multimeric analysis).

Blood tests for VWS

For diagnosis, the blood is examined using multiple and special laboratory tests. It takes a lot of specialized medical knowledge to correctly classify VWS. The VWS type or subtype can be determined based on the results. The aim of the tests is to measure and determine:

• Closure times of the blood platelets
• Interaction of coagulation factor VIII with the VW factor
• Concentration of the VWF
• Function of the VWF
• Relationship between VWF and activity VWF concentration
• Ratio of VWF and platelet receptor
• Size distribution of VWF multimers (molecules)

Von Willebrand syndrome: prevention, early detection, prognosis

If you have a family history of blood clotting disorders, you should contact a specialized center for advice, especially if you want to have children, as these disorders are hereditary and can also be relevant in connection with childbirth. Once you or your child have been diagnosed, it is important to always carry an emergency ID card with you and make us and medical staff aware of the illness. Parents, teachers and grandparents should also be informed and know what to do in an emergency. The medication will help you or your child to cope with the disease and lead a largely normal life. Of course, there are a few precautions to take and dangerous sports must be avoided. Regular medical care is important for this chronic disease.

Women with von Willebrand syndrome can of course become pregnant. Although von Willebrand factor increases during the course of pregnancy and often reaches normal levels at the due date, bleeding after delivery is more frequent than usual. Qualified medical care during pregnancy and preparation for delivery is therefore important in order to avoid unnecessary risks.

Von Willebrand syndrome - treatment, therapy

Many people with mild von Willebrand syndrome hardly need any special treatment in everyday life, but do need it before operations or tooth extractions. In many cases, mild measures are sufficient, such as the use of tranexamic acid, the administration of DDAVP and careful local wound healing. However, severe forms of von Willebrand syndrome or extensive interventions usually require the administration of concentrated von Willebrand factor over several days. Some patients with severe type 3 also receive long-term treatment (prophylaxis) with such concentrates to prevent bleeding.