Hemophilia is a congenital bleeding disorder that mostly affects males. It is estimated that less than 1 in 10,000 people, or about 2,500 Canadians have Hemophilia A and approximately 1 in 50,000 people, or about 600 Canadians have Hemophilia B.
Patients with Hemophilia A have either absent, decreased or defective production of the blood clotting protein, Factor VIII (FVIII). Those with Hemophilia B have similar problems with Factor IX (FIX). Hemophilia is characterized as "severe" when the activity of the affected clotting factor (FVIII or FIX) is less than 1% of normal. Severe hemophilia is often associated with spontaneous bleeding (i.e. bleeding not caused by trauma or injury). Hemophilia is termed "mild" when the relevant clotting factor activity is 5 to 40% of normal. Hemophilia is referred to as "moderate" when clotting factor activity is between 1% and 5% of normal. Approximately 60% of hemophilia patients have severe disease.
Severe hemophilia is often diagnosed in the first year of life. The first signs of hemophilia in a child under the age of 2 are bleeding in their gums and tongue and surface bruises from falls. In an older child or an adult, hemorrhages often occur in the joints (particularly the weight bearing joints such as knees and ankles). These joint bleeds can cause severe pain and often permanent damage and immobility. Other mild to moderate bleeds can occur in the muscles, soft tissues, or even the gastrointestinal tract. Serious bleeds can occur in the neck, throat, tongue or brain. In addition, trauma, major surgery, tooth extractions or other minor surgical interventions may result in bleeds.