About von Willebrand disease

Patients with von Willebrand disease (VWD) have deficient or defective von Willebrand factor (VWF), a protein in the blood that is important for clot formation. When a blood vessel is injured and bleeding occurs in people with VWD, it takes longer for their blood to clot and for the bleeding to stop. VWF helps blood clot in 2 ways¹:

1. VWF functions like glue to help platelets (blood-clotting cells) stick together and form a platelet plug at the site of the wound¹
2. VWF also stabilizes, protects and carries factor VIII (another clotting protein) to the site of the injury.¹ VWF prevents factor VIII from being broken down in the blood stream¹

How common is VWD?

VWD is the most common bleeding disorder, occurring in approximately 1% of the world’s population, including as many as 3 million people in the US alone.² It’s primarily a hereditary disease and occurs in women and men in equal numbers.² It is suspected that there are many undiagnosed people living with VWD.³

The unique genetics of VWD

VWD is usually passed down (inherited) from a parent to a child. In rare instances, a child can have VWD even without a family history of the disease. This can happen as a result of a spontaneous mutation (change) in the gene. The child can later pass the disease on to his or her children.²

“There are a lot of things people don’t understand about von Willebrand.” — Kelly, parent

It is rare but possible for someone to develop VWD later in life. If VWD is acquired (not inherited from a parent or a result of a gene mutation), it cannot be passed along to any children. VWD can be acquired when a person’s own immune system destroys his or her VWF, often as a result of another disease or medication usage.²

There are 3 inherited types of VWD

• Type 1 — Type 1 is the most common form of VWD. People with type 1 have low levels of VWF and may have low levels of factor VIII²
• Type 2 — Type 2 is divided into subtypes (2A, 2B, 2M, and 2N) based on the mutation that causes it. These mutations cause the VWF protein to not work properly during various stages of the clotting cascade²
• Type 3 — Type 3 is rare and is the most severe form of VWD. People who have type 3 usually have little to no VWF and low levels of factor VIII²

The diagram above shows how the mutated gene could be inherited. This diagram shows the inheritance pattern of a father who has mild VWD and a mother who does not have VWD. Each pregnancy has a 50% chance in resulting in a mild or carrier of VWD. If both parents are affected, there is a 25% chance of a pregnancy resulting in a severe type of VWD.⁴

How is VWD diagnosed?

Diagnosing VWD usually involves reviewing personal history of bleeding or bruising that is more than normal, such as⁵:

• Bleeding from a small wound that lasted more than 15 minutes or restarted within 7 days
• Prolonged, heavy, or repeated bleeding that required medical attention after surgery or a dental procedure
• Bruising with little or no apparent trauma, especially if a lump appears under the bruise
• Nosebleeds with no obvious cause, lasting longer than 10 minutes or requiring medical attention
• Bloody stools for no known reason
• Heavy menstrual bleeding in women (menorrhagia)

Some signs of heavy menstrual bleeding include⁶:
• Bleeding for longer than 7 days
• Changing a tampon or pad every 2 hours or fewer on the heaviest day
• Flooding or gushing blood that limits daily activities
• Passing blood clots larger than a quarter

Heavy menstrual bleeding may lead to anemia.⁴ Signs of anemia to watch for include weakness, tiredness, and paleness. If a woman notices any of these symptoms, she should contact her healthcare provider.⁶

Your healthcare provider will likely also research whether you have a family history of bleeding, give you a physical exam, and check for signs of liver disease or anemia (low red blood cell count).^4,5

People with severe VWD often have symptoms as babies and may be diagnosed early, but in milder cases VWD often isn’t diagnosed until adulthood. An accurate diagnosis is extremely important for women in order to avoid unnecessary and/or invasive treatments, such as hysterectomy.¹

Testing may be repeated multiple times because a person’s VWF levels can vary in different instances and may appear normal. Because routine blood tests often give normal results, VWD can only be diagnosed with several specialized blood tests.¹