vWD is the most common type of bleeding disorder, affecting an estimated 1% of the world's population.

Von Willebrand Disease affects males and females equally. However, because symptoms can be mild, many people affected have not been diagnosed. People with VWD have decreased or malfunctioning Von Willebrand factor (VWF) activity and therefore cannot form a proper platelet plug.

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VWF has two roles in blood coagulation: 

1. VWF is the protein that makes platelets stick together to form a platelet plug.

2. VWF is a carrier protein for factor VIII. VWF ensures that there is enough factor VIII in the blood stream, t carries it to the site of injury, and protects it from being broken down in the blood stream.

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Types of Von Willebrand Disease:

• Type 1 – von Willebrand levels are lower than normal

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• Type 2 – there is a defect in the structure of the von Willebrand protein that causes lower than normal VW factor protein activity.

  1. Type 2a – the level of VW factor is reduced, as is the ability of platelete to clump together

  2. Type 2b – although the VW factor is defective, the ability for platelets to clump together is actually increased.

  3. Type 2m – the VWF is not able to stick to the platelets and therefore a platelet plug is not properly formed.

  4. Type 2n – Also called type 2 Normandy. Type 2n occurs when there isn’t enough VWF to carry the factor VIII protein to the site of injury and therefore there are decreased levels of factor VIII to form a fibrin clot.

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• Type 3 – there is very little or no von Willebrand protein produced at all.

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Severity of Von Willebrand Disease:

Bleeding can be mild, moderate or severe within each type of vWD. The severity depends in part on the level of VW factor activity. Blood type plays a role in the levels of VW factor found in the blood. Type O blood often has lower levels of VW factor.

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Type of vWD               Severity

Type I                           Symptoms are usually mild.

Type II                          Symptoms are usually moderate.

Type III                         Symptoms are usually severe

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Symptoms of Von Willebrand Disease:

• Nose bleeds

• Prolonged bleeding from minor cuts

• Heavy of longer than usual menstrual bleeding

• Blood in the urine

• Blood in the stools

• Large bruises

• Hematomas

• Gums bleed easily

• Heavy periods and/or periods lasting more than 7 days

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     Causes of VWD

 

A person is born with Von Willebrand Disease. VWD cannot be caught from someone else and it cannot spread like a virus or an infections.

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VWD affect males and females equally. The majority of the cases are “inherited”, passed from parents to children through their genes. Some cases are due to “spontaneous mutations” caused by a change in the gene that carries the instructions to produce the VW factor.

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Type 1 and type 2:

• Usually inherited.

• One of the parents has the mutated gene and has a 50% chance of passing it to the child.

• Parent may not know they carry the mutated gene because their symptoms may be very mild or don’t have symptoms at all.

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Type 3:

• Type 3 is always inherited.

• Both parents pass the gene to the child.

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  Treatment of VWD

 

Treatment may vary depending on the type and severity of the disorder, as well as response to previous therapy and other medications the person may be taking. The most commonly used treatments for von Willebrand disease include:

 

DDAVP® – Desmopressin acetate is used to treat some types of von Willebrand Disease. DDAVP is usually effective in people with Type 1 and some subtypes of Type 2. The medication can be sprayed into the nose or injected into the blood stream. This is a syntheic hormone that stimulates the body to release more von Willebrand stored in the lining of the blood vessels.

 

Factor Concentrates with von Willebrand Factor – Factor concentrates are used to treat people with Type 2b and Type 3. It is also used for people with Type 2A prior to surgery or if they are experiencing severe bleeding. The brands that contain VWF include: Alphanate SD®, Humate P®, Koate DVI®, and Wilate®.

 

Contraceptives – Estrogen hormones can boost levels of VWF and factor VIII activity and therefore can help control heavy menstrual cycles. Other contraceptive devices placed in the uterus can also help reduce heavy bleeding during menstruation.

 

Anti-fibrinolytic or clot-stabilizing medications. These medications are usually prescribed before or after surgical procedures. Aminocaproic acid (Amicar) and tranexamic acid (Cyklokapron) can slow down the breakdown of clotting factors and therefore can help keep a clot in place once it has formed.

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    Inheritance Patterns of VWD

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The following diagrams show how the von Willebrand gene can be inherited.

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Inheritance of Type 1 and 2 is illustrated below:

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Inheritance of Type 3 is illustrated below:

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