March is Bleeding Disorders Awareness Month, an opportunity to learn more about bleeding disorders that can often be misdiagnosed.
A bleeding disorder is the umbrella term used to describe a variety of conditions that result in abnormal blood clotting. Separately, these conditions are relatively rare, but together, bleeding disorders impact millions of patients worldwide.
Our Derek Ansel, CCRA, Clinical Scientist, Rare Diseases, explains:
Derek will be attending the 70th National Hemophilia Foundation Bleeding Disorders Conference on October 11 -13, 2018 in Orlando, FL
Individuals with a bleeding disorder are typically diagnosed with hemophilia A or B, von Willebrand Disease (vWD), or any other rare blood clotting deficiency. Just like any genetic disease, symptoms can vary between individuals but generally include spontaneous bleeding, bruising, nosebleeds, and pain in the joints.
These symptoms all stem from the body’s inability to create a successful blood clot during injury. Treatments for these disorders often require lengthy and frequent intravenous infusions. Based on levels of factor deficiency, some patients require treatment during common surgeries, such as a tooth extraction, or during emergencies.
The coagulation cascade is a series of critical steps to ensure that a clot is properly formed when a blood vessel is faced with an injury. In the cascade, a series of factors, or blood proteins, are required to generate a clot. Deficient levels in factors VIII or IX cause Hemophilia A and Hemophilia B, respectively, and these factors are critical to the formation of a successful blood clot.
Hemophilia A and Hemophilia B
Hemophilia A affects around 1 in 5,000 males. The condition is X-linked recessive that is inherited or spontaneously occurs from a mutation and is most commonly seen in men. The F8C gene that is responsible for formation of factor VIII can see a variety of changes, deletions, and insertions that all will cause varible levels of hemophilia A.
Hemophilia B affects around 1 in 25,000 males and is less prevalent than hemophilia A. Just like hemophilia A, hemophilia B is also an x-linked recessive disorder and occurs more frequently in men. The F9 gene is responsible for formation of factor IX, and when mutated, can cause variable levels of hemophilia B.
A common myth is that women are unable or cannot contract hemophilia A or B. Because both disorders are X-linked, women may have one or two mutated F8C or F9 genes on her X chromosomes. If only one of her X chromosomes has a mutation, she is considered a carrier, but can still show symptoms of the disease.
von Willebrand disease (vWD)
vWD is the most common inherited blood-clotting disorder and arises from deficient levels of von Willebrand Factor (vWF). Just like factors VIII and IX, vWF is critical during the coagulation cascade and sufficient levels are needed to produce a blood clot.
vWD is known to occur in 1% of the global population and affects males and females equally. It is more notable in women due to heavier bleeds during pregnancy, childbirth and their menstrual periods, however, women are most often misdiagnosed.
Just like hemophilia, vWD is an inherited genetic disorder that impacts the body’s ability to successfully make a blood clot. The gene responsible for producing von Willebrand Factor is vWF, located on chromosome 12.
Treatment for these bleeding disorders require recombinant blood factors that are administered intravenously. These treatments aim to restore diminished factor levels enough to make a successful blood clot, however, infusions must be frequent to ensure that factor levels remain in a sufficient range. Additional treatments are required when a patient experiences a major bleed or requires surgery.
Clinical trials in bleeding disorders are looking to improve factor levels while minimizing the need to regularly infuse patients with recombinant factors. A novel drug approach involves gene therapy in which a functional factor gene is administered to patients with the hope of essentially curing them of their disease.
Here’s where you can learn more:
Rare Diseases Newsletter Volume 16, April 2020
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