<prompt> A 15yearold female presented to the emergency department with history of recurrent epistaxis, hematuria and hematochezia. There was a history of profuse bleeding from the umbilicus stump at birth. Previous investigations revealed normal prothrombin time, activated partial thromboplastin time, thrombin time and fibrinogen levels. Her platelet counts as well as platelet function tests were normal but urea clot lysis test was positive. Which one of the following clotting factor is most likely to be deficientFactor XFactor XIFactor XIIFactor XIII  <response>: Individuals with a positive bleeding history, particularly with features such as delayed bleeding, umbilical stump bleeding or miscarriages and in whom the initial panel of screening test is negative, should be tested for Factor XIII deficiency. 