Being diagnosed with von Willebrand disease (VWD) may lead you to wonder whether you inherited it from your parents or if you could pass it down to your children. In this article, we’ll talk about the ways that VWD can be inherited. We’ll also look at differences in the inheritance of VWD versus hemophilia.

What Is von Willebrand Disease?

VWD is an inherited bleeding disorder that makes it difficult for your blood to clot. This means that when you’re injured or have surgery, you’ll bleed longer than someone who doesn’t have VWD. You may also experience easy bruising, nosebleeds that don’t end quickly, or very heavy menstrual periods.

VWD is caused by problems with a protein called von Willebrand factor (VWF). Normally, when a person starts to bleed, VWF attaches to other proteins in the blood and to blood cells called platelets. Together, the platelets, VWF, and the other proteins form a clot to stop the bleeding. However, people with VWD have a problem with their VWF protein — either they have less VWF than normal in their blood or the protein doesn’t work as well as it should. This means that when they get hurt, it takes longer to make a clot and stop the bleeding.

Types of von Willebrand Disease

There are three types of von Willebrand disease. Type 1 VWD is the mildest and most common form. People with type 1 VWD have low blood levels of VWF and may also have less of another blood-clotting protein called factor VIII (factor 8 — Roman numerals are usually used in discussions of clotting factors).

The second most common form of VWD is type 2. People with type 2 VWD have normal VWF levels, but the protein doesn’t work like it should. This form has four subtypes (type 2A, type 2B, type 2M, and type 2N), each with differences in the way the VWF protein is impaired.

People with type 3 VWD have very little or no VWF in their blood. Type 3 VWD is the rarest form of the disease and usually has the most severe bleeding symptoms.

Genetic Patterns in von Willebrand Disease

Most people who have VWD inherit it from their parents and are born with the disease. VWD is caused by mutations (variations) in the von Willebrand factor gene. Genes are made up of DNA, and you inherit them from your parents. Genes are like an instruction manual that tells your cells what to do, such as how to make von Willebrand factor. Each copy of a gene is called an allele, and you have two alleles for every gene.

All your genes are organized on chromosomes. Each cell in your body has two pairs of 23 chromosomes, for a total of 46 chromosomes. One set comes from your mother, and the other set comes from your father.

Two chromosomes are called sex chromosomes — X and Y. Typically, people are born with either two X chromosomes (and usually assigned female at birth) or one X chromosome and one Y chromosome (and usually assigned male at birth). The other chromosomes, pairs 1 through 22, are called autosomal chromosomes.

The VWF gene is found on chromosome 12, an autosomal chromosome. This means that babies inherit one copy, or allele, of the VWF gene on chromosome 12 from their mother and one copy from their father. Because of this, you can inherit VWD from either your mother or your father.

The VWF gene is on an autosomal chromosome, so von Willebrand disease occurs equally often in males and females, according to Haemophilia Foundation Australia. Depending on what type of VWD you have, you can inherit VWD in an autosomal dominant or autosomal recessive pattern, as we describe below.

Autosomal Dominant Inheritance of VWD

One way to inherit VWD is called autosomal dominant inheritance. Type 1 and most forms of type 2 (types 2A, 2B, and 2M) are inherited in an autosomal dominant inheritance pattern. This means that one mutated copy of the VWF gene is enough to give you von Willebrand disease. So if your mother or your father has this type of VWD, you have a 50 percent chance of inheriting the mutant VWF allele and getting VWD. You also have a 50 percent chance of passing on VWD to your child.

If both the mother and the father have an autosomal dominant form of VWD, they each have a 50 percent chance of passing on a mutated allele. In this case, there’s a 50 percent chance of their child receiving one normal and one mutated allele of the VWF gene, a 25 percent chance of receiving two normal alleles, and a 25 percent chance of receiving two mutated alleles. People who inherit two mutated copies will have a more severe form of von Willebrand disease than people who inherit just one mutated copy of the VWF gene.

Autosomal Recessive Inheritance of VWD

Type 3 and type 2N VWD are inherited in an autosomal recessive inheritance pattern. This means you need two mutated copies of the VWF gene (one from your mother and one from your father) to have von Willebrand disease. If you have just one mutated VWF allele, you won’t have VWD, but you can still pass the mutated allele to your children. A person with one mutant allele that is inherited in an autosomal recessive pattern is called a carrier.

People with types 3 and 2N VWD often have parents who are carriers but don’t have von Willebrand disease. If two carriers have children, there’s a 25 percent chance of their child receiving two normal VWF alleles and a 50 percent chance of receiving one normal and one mutated allele. In both cases, the child won’t have VWD. However, there’s a 25 percent chance of inheriting a mutant allele from each parent and thus having VWD. A person with type 3 or 2N VWD will always pass down a mutant allele, but their children will be carriers and won’t have VWD unless they also receive a mutant allele from the other parent.

Inheritance of von Willebrand Disease Versus Hemophilia

Hemophilia is another bleeding disorder with symptoms similar to VWD. However, hemophilia differs from VWD in several ways, including how it’s inherited. Most cases of hemophilia are due to changes on the X chromosome, one of the sex chromosomes. Hemophilia is inherited recessively, so one healthy allele can compensate for a mutated one. According to MedlinePlus, since females have two X chromosomes, they would need to get a mutated allele from both their mother and their father to develop hemophilia. However, males have just one X chromosome, so inheriting a mutated allele from their mother means they’ll have hemophilia. This is why hemophilia is more common in males and rarer in females.

In contrast, von Willebrand disease is inherited on chromosome 12, not the X chromosome. This means that all babies have the same odds of inheriting von Willebrand disease. It’s also important to remember that most cases of VWD have a dominant pattern of inheritance, so just one mutant allele is needed to cause the disease. Because of the way VWD is inherited, this disease affects men and women equally, according to the Centers of Disease Control and Prevention.

Genetic Testing for Von Willebrand Disease

If your family members have a history of VWD or you have symptoms of a bleeding disorder, your health care provider may recommend genetic testing. Testing can help determine which type of VWD you have. Knowing if your VWD is inherited in a dominant or recessive pattern will help you understand your risk of passing on VWD to your children. Genetic testing also can tell you if you’re a carrier of a mutated VWF allele that is inherited in an autosomal recessive pattern.

You can ask your health care provider for more specific information about genetic testing for von Willebrand disease.

Talk With Others Who Understand

On MyHemophiliaTeam, the social network for people with hemophilia and their loved ones, more than 6,600 members come together to ask questions, give advice, and share their stories with others who understand life with hemophilia and other bleeding disorders.

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