Haemophilia bleeding disorder is a group of hereditary genetic disorders that impair the body’s ability to control blood clotting or coagulation. In its most common form, Hemophilia $A$, clotting factor $VIII$ is absent. In Haemophilia $B$, factor $IX$ is deficient. Factor $VIII$ participates in blood coagulation; it is a cofactor for factor $IXa$ which, in the presence of $Ca^{+2}$ and phospholipids forms a complex that converts factor $X$ to the activated form $Xa$. Defects in this gene results in hemophilia $A$, a common recessive $X-$ linked coagulation disorder. Prothrombin producing platelets in such persons are not found in very low concentration.