A guide to understanding Hemophilia and related bleeding disorders
Many types of inherited bleeding disorders affect individuals worldwide, and each calls for its own unique treatment protocol. Among these bleeding disorders are hemophilia A, hemophilia B, and several other rare disorders characterized by deficiencies in clotting factors. Compared to hemophilia, Von Willebrand disease is a more common bleeding disorder, affecting as much as 1 to 2 percent of our population.
Hemophilia is a disorder with a person’s blood-clotting system that can result in excessive bleeding, infection and joint damage. Blood contains 20 distinct clotting factors that contribute to its ability to cease flowing upon an injury.The two most common types of hemophilia — hemophilia A and hemophilia B — are defined by a deficiency in these clotting factors.
Defining Hemophilia A
Hemophilia A is an inherited disorder resulting in the deficiency of functional plasma coagulation factor VIII. In addition to inheritance, significant rates of spontaneous mutation, almost 30 percent, as well as acquired immunologic processes, can result in this disorder. Morbidity and death are primarily the result of hemorrhage. However, over the past 20 years, infectious diseases (i.e., HIV, hepatitis C) have become prominent in patients who received blood products prior to 1985.
In the United States, there are an estimated 17,000 individuals affected with hemophilia A.
Factor VIII deficiency can lead to a disruption of the normal intrinsic coagulation cascade, resulting in spontaneous hemorrhage or excessive hemorrhage in response to trauma. Hemorrhage sites usually include the joints, muscles and the gastrointestinal system, followed by the central nervous system (CNS), the genitourinary system, and the pulmonary system. Patients who also have acquired HIV or hepatitis suffer from maladies associated with these infections.
In the United States there are an estimated 17,000 individuals affected with hemophilia A. Approximately one in 5,000 to one in 10,000 males is born with the disorder. Although extremely rare, women can also have hemophilia. Hemophilia occurs across all racial and ethnic groups. Occurrence rates of hemophilia among white, African-American, and Hispanic males in the United States are similar.
The levels of severity of the disease can be broken down into mild, moderate and severe. Normal factor VIII activity is 50 to 200 percent. In severe cases of hemophilia, factor VIII activity is less than 1 percent. In moderate cases it is between 1 and 5 percent activity, and in mild disease, activity is greater than 5 percent.
Severe disease will often be present in infancy or childhood and can manifest itself as bleeding, such as with circumcision, joint bleeds, and muscle bleeds. CNS bleeds occur most commonly in newborns. Patients with mild or moderate disease usually do not have spontaneous bleeding, and the presence of disease often remains undetected until the individual undergoes a surgical or dental procedure.