VWD is almost always inherited. This means it is passed from parent to child through their genes. Genes are the instructions that control our growth and how our bodies work. VWD can occur when the gene that contains instructions for producing the VWF protein is altered. This is sometimes known as a fault or mutation.
You can inherit type 1, 2 and pseudo-VWD, which are all passed on in an autosomal dominant manner. This means that only one of your parents passes a faulty VWF gene on to you. For each pregnancy there is a one in two chance that the child will have VWD.
You can inherit type 3 VWD if both your parents pass a faulty VWF gene on to you (autosomal recessive manner). Your symptoms may be quite different from your parent or parents’ symptoms.
There is also an ‘acquired’ type of VWD that can develop later in life, often as a result of another condition. This is not covered in this booklet.
In some cases, you can have a faulty VWF gene without any symptoms of VWD. However, you can still pass the faulty VWF gene on to your children.
The type of VWD a person is born with mostly depends on whether they inherit copies of this faulty gene from one or both parents.
- If one parent has a genetic fault that causes VWD – there is a 1 in 2 (50%) chance of a child having type 1 or type 2 VWD, and no chance of them having type 3 VWD.
- If both parents have a fault in the gene – there is a 1 in 2 (50%) chance of a child being a carrier like their parents and a 1 in 4 (25%) chance of them having type 3 VWD.
The chances of inheriting mild forms of type 1 VWD can also be affected by other things, including blood group: people with blood group O are more often affected than people with blood group A or B.
This means it is not always easy to predict whether a child might inherit it from their parents.
Parents who are carriers of a faulty VWF gene may not have symptoms themselves.
More information is available in our Understanding von Willebrand Disease booklet.