Which are the causes of Von Willebrand Disease?

Von Willebrand Disease (VWD) is primarily caused by a deficiency or dysfunction of the von Willebrand factor (VWF), a protein essential for blood clotting. This condition is most often inherited through genetic mutations that affect the production or structure of this protein, though it can occasionally be acquired later in life due to other underlying medical issues.

What causes Von Willebrand Disease at a genetic level?

The primary cause of Von Willebrand Disease is a mutation in the VWF gene, located on chromosome 12. This gene provides the instructions to create the von Willebrand factor protein, which acts like "glue" to help platelets stick together and repair damaged blood vessel walls. When the gene is mutated, the body may produce too little of this protein, or the protein may be malformed and unable to function correctly. In most cases, Von Willebrand Disease follows an autosomal dominant inheritance pattern, meaning a child has a 50% chance of inheriting the condition if one parent carries the mutation.

What is the difference between inherited and acquired Von Willebrand Disease?

While most cases are congenital (present from birth), there is a distinct form known as Acquired von Willebrand Syndrome (AVWS). Unlike the inherited form of Von Willebrand Disease, AVWS is not caused by a genetic mutation passed down through families. Instead, it occurs when the body’s own immune system or another underlying disease process interferes with the von Willebrand factor. For example, conditions such as lymphoproliferative disorders, hypothyroidism, or certain cardiovascular diseases can lead to a secondary reduction in VWF levels.

What are the different types of Von Willebrand Disease?

The underlying cause determines the classification of the condition, which helps physicians tailor treatment. The following list outlines the primary categories of Von Willebrand Disease based on their pathophysiology:

• Type 1: The most common form, characterized by a partial quantitative deficiency (not enough protein is produced).


• Type 2: A qualitative defect where the von Willebrand factor protein is produced but does not function correctly due to structural abnormalities.


• Type 3: The most severe form, usually resulting from two mutated copies of the gene (one from each parent), leading to a near-total absence of the protein.


• Acquired (AVWS): A non-genetic form caused by the rapid clearance of VWF from the blood, often due to an underlying autoimmune or malignant process.

Is the cause of Von Willebrand Disease fully understood?

While the genetic basis for most forms of Von Willebrand Disease is well-documented, researchers are still actively studying the nuances of how specific mutations affect protein folding and interaction with other clotting factors. Current research focuses on better understanding the "modifier genes" that may explain why two people with the same mutation can have vastly different bleeding symptoms. Furthermore, at the DiseaseMaps.org community, where 184 members have shared their experiences, ongoing data collection helps researchers understand how environmental and lifestyle factors influence the severity of Von Willebrand Disease symptoms in daily life.

Next steps

• Consult a hematologist specializing in bleeding disorders to determine your specific type and severity.


• Consider genetic counseling if you are planning a family to understand the inheritance risks.


• Join the community at DiseaseMaps.org to connect with others and share experiences regarding management and care.


• Keep a detailed log of bleeding episodes to assist your medical team in refining your treatment plan.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician with any questions regarding a medical condition.

References

• National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD): Von Willebrand Disease.


• Orphanet: Von Willebrand disease (ORPHA:908).


• Online Mendelian Inheritance in Man (OMIM): Von Willebrand Factor (VWF) gene entry (#193400).


• World Federation of Hemophilia: Guidelines for the Management of Von Willebrand Disease.