Haemophilia is a hereditary bleeding disorder that affects males. Approximately 1 in 5,000 males is born with haemophilia. An estimated 400,000 males have haemophilia A or B. According to the World Federation for Hemophilia, only 25% have confirmed diagnosis and access to adequate care. An estimated 75% of people with haemophilia live in the developing world.
Patients with haemophilia A have either decreased, defective or absent production of the blood clotting protein, factor VIII. Those with haemophilia B have similar deficiencies with clotting factor IX. For people with haemophilia, bleeds often occur in the joints, particularly knees and ankles. Bleeds can also occur in the muscles, soft tissues, gastrointestinal tract or even the brain. Trauma, major surgery, tooth extractions or other minor surgical interventions require medical intervention to manage the associated bleeding. Without treatment bleeds are painful and can cause lasting damages and lead to impaired mobility.
Haemophilia is characterised as "severe" when the activity of the affected clotting factor (FVIII or FIX) is less than 1% of normal. Severe Haemophilia is often associated with spontaneous bleeding, i.e. not caused by injury. Haemophilia is termed "mild" when the relevant clotting factor activity is greater than 5%, but less than normal and "moderate" when clotting factor activity is between 1% and 5% of normal. Approximately 50% of haemophilia patients have severe disease and can require treatment for bleeding several times per month.