All About von Willebrand's Disease

While still rare (affecting roughly 1% of the world’s population), von Willebrand’s disease is the most common form of bleeding disorder in the world.

The Difference Between Hemophilia and von Willebrand’s Disease

Although they are both bleeding disorders, von Willebrand’s (VWD) disease is not the same as hemophilia. Hemophilia is a rare inherited bleeding disorder in which blood cannot clot normally due to missing or low levels of specific clotting factors such as FVIII (hemophilia A) or IX (hemophilia B).

VWD?
Von Willebrand’s disease, on the other hand, is caused by a defect or deficiency in the von Willebrand factor (VWF). VWF is a specialized clotting protein made by endothelial cells which line the inside of blood vessels and bone marrow cells.

Some people with VWD have the right amount of the von Willebrand factor, but it is structurally defective and therefore does not clot normally. Additionally, some people with VWD also have lower counts of factor VIII.

Hemophilia
Both hemophilia and VWD have strong genetic components and are usually inherited, but not in the same way. Hemophilia is carried on the X chromosome. (X and Y chromosomes are the sex chromosomes responsible for gender), which is why it occurs predominantly in males. Females can be carriers of hemophilia, and some do experience symptoms of the disease in some cases. Click here.

In contrast, Von Willebrand’s disease is caused by a mutation carried on chromosome 12 (a non-sex chromosome). This means it occurs equally in both males and females.

VWD and Chromosome 12
Generally speaking, the symptoms of VWD are less severe than those of hemophilia, but they can be serious and even life-threating in severe cases.

There is currently no cure for either hemophilia or von Willebrand’s, however both forms of bleeding disorders are manageable with proper treatment.

Acquired von Willebrand’s Disease (AVWD)
Von Willebrand’s can happen spontaneously. When it does, it is known as acquired von Willebrand’s disease, or AVWD. When this happens, it is often associated with other medical conditions such as autoimmune disorders, hypothyroidism, and certain cancers.

Von Willebrand’s Disease Symptoms
Symptoms of VWD can vary from mild to severe. In some cases, they may be absent altogether, or develop later in life. Because symptoms can be mild, it is estimated that as many as 9 out of 10 people with the disease are never diagnosed.

Men and women can both present with symptoms. Women, however, tend to have more problems since this disease is associated with mucosal bleeding. Symptoms in females can include excessive bleeding after childbirth, or heavier and longer menstrual periods.

Symptoms of von Willebrand’s Disease

• Easy bruising
• Blood in the urine or stools
• Exaggerated or excessive bleeding from injuries
• Excessive bleeding after surgery or dental work
• Heavy menstrual bleeding
• Nosebleeds that last longer than ten minutes
• Symptoms of anemia, fatigue and or shortness of breath

What is the Von Willebrand Factor?
The von Willebrand factor is a special blood protein that is critical to normal clotting. It is named after Erik Adolf von Willebrand, a Finnish doctor who made major contributions to the field of hematology, including discovering the bleeding disorder that bears his name in 1927.

What is Blood Clotting?
Clotting is what happens when blood changes from a liquid form to a gel, and then forms a stronger form of clot called a fibrin clot in order to prevent excessive bleeding from damage to a blood vessel.

The clotting process can be divided into two main stages known as primary hemostasis and secondary hemostasis. In the primary, or first stage, a soft plug is formed. In the last stages of clotting, the stronger fibrin clot is created.

There are also different pathways in which clotting can occur, including the intrinsic and extrinsic pathways. Suffice to say that the extrinsic pathway is activated by external trauma, and the intrinsic pathway involves factor VII.