Understanding Hemophilia

There are two general types of clotting disorders. With Hemophilia and Von Willebrand Disease, clotting is inadequate, leading to potentially dangerous blood loss. Other clotting disorders cause excess clotting, which can block arteries and veins, resulting in serious complications.

Types of Hemophilia

• Hemophilia A, the most common type, is due to a lack, or insufficient amount of, the blood clotting factor VIII. Roughly nine out of ten people with hemophilia have type A disease.
• Hemophilia B is caused by the absence or inadequate levels of blood clotting factor IX.
• Hemophilia C is an extremely rare condition caused by the lack of clotting factor XI. While Hemophilia C does not usually cause spontaneous bleeding, it can manifest as excess bleeding after surgery.
• Acquired Hemophilia is a rare autoimmune disorder in which the body produces antibodies against clotting factors. Most cases occur in people middle-aged and older or in young women who have recently given birth or are in the third trimester of pregnancy. Acquired hemophilia can also be associated with cancer, multiple sclerosis, and drug reactions.

The amount of clotting factor in the blood determines the severity of hemophilia. The condition is diagnosed when clotting factor activity is less than 40% of normal. Clotting factor activity higher than 5%, but less than 40% is considered mild hemophilia. The clotting factor for moderate hemophilia is between 1% and 5%. In severe hemophilia, the clotting factor activity is lower than 1%. People with severe hemophilia can experience bleeding during regular activities, sometimes with no known injury.

Symptoms of Hemophilia

Heavy, uncontrollable bleeding, both internal and external, is the hallmark of this disorder. Symptoms may include:

• Bruises from even small accidents – babies are often diagnosed when bruising becomes more apparent as they start crawling and learning to walk
• Bleeding mouth or gums, often while brushing or flossing the teeth or during dental work
• Frequent nosebleeds that are hard to stop
• Bleeding into a joint (hemarthrosis), the most common sites of complications of hemophilia, can recur repeatedly and lead to chronic arthritis, deformity, and impaired movement over time
• Bleeding into the muscles can cause inflammation, pain, and redness and lead to permanent damage to tissues and nerves
• Bleeding in the brain can happen from an injury or on its own –a minor bump or fall can have devastating complications similar to those from a hemorrhagic stroke, such as blindness, intellectual disability, neurological deficits, and even death
• Blood in the urine or stool
• Bleeding in the soft tissues, muscles, and gastrointestinal tract, frequently associated with acquired hemophilia

What Causes Hemophilia?

According to the US Centers for Disease Control and Prevention (CDC), hemophilia occurs in approximately 1 in 5,617 live male births. Between 30,000 and 33,000 US males are living with hemophilia. Nearly a third of people with hemophilia have no family history of the disorder, in which case their condition is likely due to a spontaneous genetic mutation.

The reason Hemophilia A and B primarily affect males is because these inherited diseases are passed on via a gene on the X chromosome. Because females have two X chromosomes, they are at a lower risk for hemophilia than men, who have one X and one Y chromosome. If a pregnant woman has the hemophilia gene on one of her X chromosomes, there is a 50/50 chance she will pass it on to her baby. If that baby is a boy, he will have the disease. If the baby is a girl, she will be a carrier of the disease. When a man with hemophilia has a child with a woman who is not a carrier, none of their sons will have hemophilia, but ALL of their daughters will be carriers. Women who are carriers may have very minor symptoms including bruising easily, bleeding more with surgery or dental work, nosebleeds, and heavy periods. For a woman to have more serious symptoms, she has to have the hemophilia gene on both her X chromosomes, which is statistically quite rare.

Treating Hemophilia

The standard treatment for both hemophilia A and B is to replace the missing blood clotting factor. This can be done intravenously, using commercially prepared clotting factor concentrates. People with hemophilia can learn to perform these infusions themselves, both to prevent bleeding episodes and to stop an episode in progress. In people with hemophilia A, several non-factor drugs are also available to help prevent bleeding episodes, including Emicizumab (Hemlibra). Rather than being injected into a vein, this medication is given via an injection under the skin. It can also be self-administered.

Gene therapy, in which copies of the gene that helps the body make clotting factor are injected into the body, is an option for people with both hemophilia A and B. This process is a one-time infusion that permanently raises the amount of clotting factor in the blood. However, gene therapy for hemophilia is prohibitively expensive may not be covered by insurance.

15% to 20% of people with hemophilia A or B develop an antibody that disables the clotting factors being used to prevent bleeding episodes. This makes the condition much more challenging and expensive to treat. People who have these antibodies often experience more joint disease and other bleeding problems that impact their quality of life. In cases like this, additional treatments may be needed such as a surgical product called a fibrin sealant used to form a clot to stop bleeding and help heal wounds.

This article first appeared in the April 2025 edition of the HealthPerks newsletter.