Hemophilia is an inherited disorder that affects the blood’s clotting capacity. Normally, when a person cuts themselves, clotting factors in the blood bind with platelets and blood cells to make it sticky, which eventually prevents bleeding.
Platelets are very important in the blood clotting process because their sticky surfaces help them bind together and stop bloodflow. The clotting factors then from a mesh around the platelets to hold them in place. In hemophilia, however, a deficiency in these clotting factors means bleeding continues for a longer period than usual.
Types of hemophilia
Hemophilia is categorized according to which clotting factor is deficient. In hemophilia A, clotting factor VIII is deficient and in hemophilia B, clotting factor IX is deficient. Most cases of hemophilia are hemophilia A.
The symptoms of hemophilia range from mild to severe depending on the level of clotting factors present in the blood. In most cases, the condition is severe and people are at risk of internal bleeding. This causes pain and stiffness in the joints and muscles, which can eventually become permanently damaged.
Who is affected?
The inheritance pattern of hemophilia means that mainly males are affected by this condition. Estimates show that around one boy in every 5,000 is born with hemophilia A and around 1 in every 30,000 is born with haemophilia B. Females who carry the haemophilia gene may also experience problems with bleeding such as heavy periods.
Diagnosis and treatment
Diagnosis is confirmed by blood tests to check whether the blood is clotting properly. The platelet count, prothrombin time (PT) and activated partial thromboplastin time (aPTT) are checked. If the platelet count and PT are normal but the aPPT is prolonged, hemophilia is indicated. Specific tests to check the clotting factor levels can then be carried out to confirm a diagnosis.
Hemophilia cannot be cured but people with the illness can manage their condition using medication and still enjoy a good quality of life. Genetically engineered clotting factor medications are now routinely administered to prevent and treat prolonged bleeding.
Reviewed by Sally Robertson, BSc