What is von Willebrand Disorder (VWD)?
Von Willebrand disorder (VWD) is an inherited bleeding disorder. People with VWD have a problem with a protein in their blood called von Willebrand factor (VWF) that helps control bleeding. They do not have enough of the protein or it does not work the way it should. It takes longer for blood to clot and for bleeding to stop.
How common is VWD?
VWD is the most common inherited bleeding disorder worldwide. It affects both males and females from all racial backgrounds.
Most people with VWD are born with the disorder as VWD is inherited genetically. Sometimes VWD will show up when the person is a child. Others don’t find out until they are adults and have a bleeding problem, or until a relative is diagnosed and it is suggested that they are tested as well.
It is estimated that VWD affects approximately 200,000 people in Australia, but most people will have few or no symptoms. Many people with VWD may not know they have the disorder because their bleeding symptoms are very mild. Research suggests that many people with VWD have not yet been diagnosed.
Usually VWD is less severe than other bleeding disorders, such as haemophilia. The form causing moderate bleeding problems is uncommon, and the severe form of VWD is rare.
There are three main types of von Willebrand disorder. Bleeding symptoms can vary from person to person within each type.
Date last reviewed: June 2010
- Type 1 VWD is the most common form. Around 80% of all people with VWD have this form. In type 1 VWD, the von Willebrand Factor (VWF) works normally, but there is not enough of it. Symptoms are usually mild, depending on the level of VWF in the blood. In type 2 VWD, the amount of VWF in people’s blood is often normal but the VWF doesn’t work properly.
- Type 2 VWD is divided into subtypes 2A, 2B, 2M and 2N. Certain subtypes may be treated differently, which makes knowing the exact type of VWD you have very important.
- Type 3 VWD is very rare. People with type 3 VWD have very little or no VWF in their blood. Symptoms are more severe and can also include joint and muscle bleeding. Bleeding can occur more often.
The symptoms of VWD vary greatly from person to person. Even members of the same family may have different symptoms.
Most people with VWD have few or no symptoms.
The more common symptoms are:
- Having nose bleeds often or that are difficult to stop
- Easy bruising
- Very heavy or long menstrual periods
- Bleeding for a long time with minor cuts
- Bleeding from the gums
- Bleeding after injury, surgery or dental work that continues for a long time
Bleeding in people with VWD usually involves the mucous membranes, the delicate tissues that line body passages such as the nose, mouth, uterus, vagina, stomach and intestines.
Less common symptoms that older people might experience are:
- Blood in faeces (bowel motions/poo) from bleeding in the intestines or stomach
- Blood in urine from bleeding in the kidneys or bladder
People with severe forms of VWD, particularly type 3 VWD, may also have other bleeding problems similar to haemophilia, such as:
- Bleeding episodes that are spontaneous or happen for no obvious reason.
- Bleeding into joints and muscles which can cause swelling and pain.
The types of symptoms a person with VWD experiences can change over their lifetime. For example, they may have nosebleeds and easy bruising as a child and find this occurs less often as they grow older. However, their type of VWD will not change.
Women are more likely to show symptoms of VWD than men. Without treatment, women with VWD often bleed more or for longer than normal with menstruation (their period). Some women with VWD also have heavy bleeding a few days or weeks after giving birth and some have a lot of period pain or irregular periods. However, these symptoms are not always related to VWD and may have other causes. An assessment by a gynaecologist is an important part of understanding and treating these symptoms effectively.
Date last reviewed: June 2010
How is von Willebrand Disorder inherited?
Von Willebrand disorder is mostly a genetic disorder. This means it is passed down through the genes from parent to child. The altered gene in von Willebrand disorder is on one of the regular chromosomes, not on one of the sex chromosomes (like haemophilia). This means that, unlike haemophilia which affects more males, von Willebrand disorder affects males and females in equal numbers.
There are two main inheritance patterns for VWD:
In most type 1 and type 2A, 2B and 2M VWD, the VWD gene is dominant. This means that if one parent has a VWD gene, they have a one in two (50%) chance of passing the gene on to each of their children. They or their children may or may not have symptoms.
In type 3 and type 2N and some type 1 and 2A VWD, the VWD gene is recessive. If both parents carry this type of VWD, they may not have symptoms but there is a one in four (25%) chance that their children could inherit a copy of the VWD gene from both of them and have symptoms, usually severe. There is a one in two (50%) chance that their children will inherit only one copy of the VWD gene from them and carry the gene but not have symptoms, like their parents. There is also a one in four (25%) chance that their children will not inherit the VWD gene at all.
If one member of a family is diagnosed with VWD, the doctor may recommend testing other members to see whether they have VWD as well.
Date last reviewed: June 2010
VWD can be difficult to diagnose and repeated testing may be needed to confirm the diagnosis.
Many people’s symptoms are mild and they may not be diagnosed until they have a major bleeding problem, eg from surgery or an injury. However, if they have a severe form of VWD, they will usually have major bleeding problems as a baby or small child and will often be diagnosed within their first year of life.
Diagnosing VWD involves:
- A personal history of bleeding or bruising more than normal from mucous membranes or skin after injury, trauma or surgery and
- A family history of bleeding more than normal and
- Specialised laboratory test results for VWD
Tests for VWD
The doctor may order several laboratory tests on blood samples:
- Von Willebrand factor antigen: to measure the amount of von Willebrand factor in your blood
- Von Willebrand factor ristocetin cofactor activity and/or the collagen binding assay: to show how well the von Willebrand factor works
- Factor VIII clotting activity: to measure how well the von Willebrand factor binds to the factor VIII protein and maintains the level of factor VIII in the blood. Some people with VWD have low levels of factor VIII, while others have normal levels
- Von Willebrand factor multimers: if some tests suggest you have VWD, this test is used to show the makeup or structure of the von Willebrand factor and helps to diagnose the type of VWD
- Platelet function test: to measure how well your platelets are working.
Understanding the laboratory test results is complex and needs to be done by a haematologist (specialist doctor) and laboratory with experience in VWD.
VWD can only be diagnosed with specialised blood tests. Routine blood tests often give normal results, which is why the person’s history of bleeding is so important. Testing is often repeated because a person’s VWF and factor VIII levels can vary at different times. For example, several common experiences can cause the level of VWF to rise in the blood and appear to be normal:
- Normal hormonal changes during a woman’s monthly menstrual cycle
- Hormone treatment.
Inflammation with other health problems or blood type can also affect levels of VWF and factor VIII in the blood. People with type O blood often have lower levels of VWF.
If you think you have a bleeding problem, it is important to see a haematologist who specialises in bleeding disorders. In Australia, these haematologists can be found at Haemophilia Centres or Services which are at some major hospitals. Talk to your general practitioner or your gynaecologist about a referral.
There are a variety of issues related to diagnosing VWD, including:
- Other family members may need to be tested for VWD
- Possible implications for employment, health insurance cover and carrying the VWD gene
- Decisions will need to be made, in consultation with your Haemophilia Centre or Service, about which treatment options will be the most suitable.
Haemophilia Centre social workers, counsellors and nurses are available to help people deal with these issues.
Date last reviewed: June 2010
Specialist Haemophilia Centres or Services have a team of health professionals with expertise in providing treatment and care to people with bleeding disorders including VWD. They can work with the person with VWD to make a treatment plan and advise on ways to live well with VWD.
The team includes:
- Haematologists: doctors who specialise in blood disorders
- Haemophilia nurses
- Social workers or counsellors
- Other specialist health professionals
The recommended treatment for VWD can depend on the type of VWD a person has and how severe it is. Usually people with mild VWD will only need treatment if they have surgery, dental work or an accident or injury.
For some minor bleeding problems, like bruising, treatment may not be necessary.
If people do need treatment at times, there are several treatments available. Which treatments will be used on particular occasions will depend on the person’s medical needs, what works best for them and the situation. The haematologist will consider all of this when they work with the person to decide the best treatment option.
Desmopressin (DDAVP) is a synthetic hormone. It works by releasing the body’s stored VWF and factor VIII into the bloodstream to help blood clot. These stores are limited, so a person may need to wait for the body to rebuild its stores of VWF before taking another dose, usually about 24 hours. Desmopressin can be given as a slow injection into a vein, but may also be given as an injection subcutaneously (into the fatty tissue under the skin), or in special circumstances as a nasal spray.
Desmopressin can help to prevent or treat bleeding in many people. It is not suitable for everyone. The haematologist at the Haemophilia Centre may decide to give a test dose of desmopressin and evaluate whether it will work for that particular person. This test may need to be repeated at times as people’s responses to DDAVP change at different times in their life.
Clotting factor concentrate made with von Willebrand factor (VWF) and factor VIII (FVIII) replaces the missing VWF and FVIII in the blood and helps blood to clot. This clotting factor concentrate is made from the plasma (pale yellow fluid part) in human blood and is produced from blood donations.
This clotting factor concentrate is used when DDAVP is not suitable, or when it is likely the person will need treatment for more than 2-3 days, eg after major surgery. The treatment is infused (injected) into a vein in the arm.
Tranexamic acid and aminocaproic acid are medicines that stop blood clots being dissolved once they have formed. They can be used to stop bleeding in the mouth or nosebleeds, gut bleeding, bleeding after dental work, minor surgery or an injury.
Most commonly they are taken as tablets, syrup or as a mouthwash. They may be used by themselves or together with DDAVP or a clotting factor concentrate.
Fibrin glue is a medical gel made from fibrinogen and thrombin, which are proteins in the body that help blood to clot. It can be applied directly onto a wound to stop bleeding.
Date last reviewed: June 2010
Hormone treatment, such as oral contraceptives (birth control pills), can help women who have heavy menstrual bleeding. The hormones can increase VWF and factor VIII levels.