Factor XIII Activity test is recommended by the doctors in order to detect homozygous, heterozygous along with deficiency or decreased levels of Factor XIII (FXIII). This test also indicates those patients who have a genetic bleeding disorder which is caused due to factor xiii deficiency. That forms blood clots and due to instability they breakdown resulting in uncontrolled bleeding. FXIII is a combination of two subunits A and B. It is considered that FXIII deficiency is mostly due to the mutations in subunit A and lesser times due to mutations caused in subunit B. Though the symptoms of FXIII can be recognized at any age, but still in most of the cases it is diagnosed in infancy only.