en Pediatric Hematology & Oncology Pediatric Hematology & Oncology گزارش مورد Case report Coagulaon factor XIII gene, protein structure and funcon Coagulaon factor XIII (FXIII) is a tetrameric (FXIII- A2B2) pro-transglutaminase enzyme with an essenal role in the final stage of coagulaon cascade by cross linking the fibrin monomers and stabilizing the fibrin clot. Congenital FXIII deficiency is a rare bleeding disorder, with an autosomal recessive trait inheritance, and a frequency of about 1 in 2 million people. Most cases of FXIII deficiency are associated with FXIII-A subunit deficiency and only few FXIII-B subunit deficiencies have been reported. Severe FXIII-A deficiencies are associated with some moderate to severe clinical complicaons including umbilical bleeding during infancy, impaired wound healing, pregnancy loss in affected women, life-threatening intracranial bleeding and also subcutaneous and so# ssue bleeding. Diagnosis of FXIII deficiency can be achieved by clot solubility tests in 5 M urea or 1% monochloracec acid as a screening assay, and also quantave evaluaon of the acvity or angenic levels of FXIII A and B subunits. There have been recommendaons for primary prophylaxis or replacement therapy in FXIII deficient paents, in order to prevent spontaneous bleeding, bleeding during minor and major surgeries, or prevenon of pregnancy loss in women. Acquired FXIII deficiency has also been reported as a result of decreased producon or high consumpon of FXIII as well as the secreon of autoanbodies against FXIII subunits. FXIII deficiency, bleeding disorders, wound healing, pregnancy, prophylaxis, replacement therapy 85 91 http://ijbc.ir/browse.php?a_code=A-10-48-12&slc_lang=en&sid=1