Hemophilia

Hemophilia is an inborn disorder in which blood is in short supply of sufficient blood-clotting proteins, also known as clotting factors, and doesn’t coagulate normally. A person with hemophilia may bleed for longer period even after minor cuts, injuries, or following vaccination. Severe deficiency of the clotting proteins in plasma can give rise to serious bleeding in various parts of the body, especially in the knees, ankles, or the brain. These clots arising from internal bleeding can damage the tissues and organs which may be life-threatening. Clotting of blood is the result of complex interaction between clotting factors through enzymatic processes in which blood changes from a fluid phase to a gel, forming a clot. Several factors participate in the mechanism of blood coagulation that function in a sequence causing constriction of blood vessel, activation, adhesion and aggregation of platelets, formation and deposition of fibrin from the plasma protein fibrinogen.

Hemophilia can occur with the deficiency in one of the clotting factors. Although the most forms of hemophilia are inherited, about 30% of hemophiliacs have no family history of the genetic disorder. In the most common types, the faulty gene is located on the X chromosome. This change or mutation in the gene can prevent the clotting protein from working correctly or missing altogether. There are two main types of hemophilia: (i) hemophilia A, which occurs due to low amounts of clotting factor VIII, and (ii) hemophilia B, which occurs due to low clotting factor IX. Other types include hemophilia C, which occurs due to low levels of factor XI. The best treatment of hemophilia is through regular injection of the reduced specific clotting factor or the clotting factor concentrates into the vein. The clotting factors are made either from human blood or by recombinant DNA technology. [Laila Noor Islam]