Von Willebrand Disease

VWD is usually caused by a fault in the gene responsible for the production of Von Willebrand factor. This genetic faultcan be passed on to a child by one or both of their parents.

There are four different types of VWD. The condition is classified according to the amount and function of the Von Willebrand factor in the blood.

The main types are:

• Type 1 The mildest and most common type. People with type 1 VWD have a reduced level of Von Willebrand factor in their blood. Symptoms might be so mild they never know they have VWD. They don't usually bleed spontaneously, but can bleed significantly if they have surgery, injure themselves or have a tooth removed.
• Type 2 In this type, which can itself be divided into four further subtypes, the Von Willebrand factor doesn't work properly. The symptoms of type 2 VWD are often more severe than type 1, but milder than type 3.
• Type 3 People with this rare type have very low levels of Von Willebrand factor in their blood, or none at all. This causes problems similar to haemophilia . Bleeding from the mouth, nose and bowel from an early age is typical, and joint and muscle bleeds can occur after injury.
• Pseudo, or platelet type this is similar to type 2, but instead of the abnormality occurring in the Von Willebrand factor, it occurs in the platelets.

Types 1, 2 and pseudo-VWD are often passed on through "autosomal dominant inheritance". This means that only one parent has to pass a copy of the faulty gene to their child for them to develop the condition.

Type 3 VWD is passed on through "autosomal recessive inheritance". This means the child needs to inherit a copy of thefaulty gene from both parents. In such cases, the parents may have no symptoms themselves because they may have only inherited a copy of the faulty gene from one of their own parents, rather than both.

You will also be asked about your family history to check if any other members of the family have a bleeding disorder.