Background and Objectives: Factor XIII is the last enzyme in the clotting cascade. The gene of A chain is located on chromosome 6. Deficiency of factor XIII in autosomal recessive conditions occurs at a frequency of 1 in 2 million general population. The aim of this study was to detect the mutations of subunit A in both patients and carriers.Materials and Methods: In this study we have investigated the molecular basis of inherited FXIII deficiency among patients from 21 unrelated Iranian families. Mutation were detected by amplifying each exon. Those exons exhibiting the presence of hetero duplex formation sensitive gel electrophoresis, were selected for direct sequencing. After sequencing, detected mutation was carried out by restriction fragment length polymorphism (RFLP).Results: All patients having entered the study had mutations. Twelve patients had homologues substitution of TGG®CGG in exon 4, 1 insertion mutation occurring in exon 7 triple G, 2 patients demonstrated mutation exon 9 ATG®AAG, 3 patients had substitution of CGG®CAG in exon 10, and 3 patients showed a homologue subsituation mutation in exon 15 GCC®GTC.Conclusions: Our findings suggest that the activity of enzyme is highly dependent on the core domain. Changes in charge, amino acid tail and conformation lead to decreased enzyme activity. Also tetrameric structure is calcium related. It seems that changes of amino acid sequence convert enzyme stability.

Background and Objectives: Factor XIII deficiency is one of the rarest bleeding disorders with an estimated prevalence of 1 in 1-3 million in the general population. The main clinical manifestations of the disease are delayed wound bleeding, recurrent miscarriage, intracranial bleeding, and umbilical cord bleeding. The prevalence of the disease in the regions such as Sistan and Baluchistan with consanguinity marriages is higher. The aim of this study was to assess the diagnosis and treatment of factor XIII deficiency in Sistan and Baluchistan province.Materials and Methods: This descriptive study was performed on 205 patients with the severe factor XIII deficiency. The diagnosis of the disease was done by a wide spectrum of characteristics including family history, clinical manifestations, laboratory tests, clot solubility in 5 M urea or monochloroacetic acid 1% environments.Results: It seems that Khash city has the highest prevalence of the disease worldwide. The molecular analysis of the patients showed that an identical homozygote mutation TGG®CGG at codon 187 in exon 4 of catalytic A subunit is responsible of this deficiency. The common manifestations of the disease at time of diagnosis were umbilical bleeding (84.4%), deep soft tissue haematoma (54.4%), and less frequently gum bleeding and finally ecchymosis.Conclusions: It seems that Sistan and Baluchistan province has the highest prevalence of factor XIII deficiency worldwide with a dramatic increase of 46 cases in 2008 to 205 patients in 2012 that alarmed the absence of a screening test in this region.

Background: Factor XIII deficiency is a bleeding disorder that its prevalence in the general population is about 1 in 2 million people around the world. In Iran, the high rate of consanguineous marriages lead to high rate of disorder with 473 factor XIII deficient patients that is about 12 times higher than the global prevalence of disorder.Methods: The study is a comprehensive review of all aspects of factor XIII deficiency in Iran.Results: The distribution of the disease in different parts of Iran shows that Sistan and Baliuchistan province not only has the largest number of patients with factor XIII deficiency in Iran, but also the world's highest incidence of the disease has been reported in this area. In Iranian patients, bleeding from the umbilical cord, hematoma and prolonged bleeding are the most common clinical presentations. Several disease-causing mutations are observed in Iranian patients with the most common mutation being factor XIII deficiency with Trp187Arg in southeast of Iran. Traditionally, patients with factor XIII deficiency were treated with fresh frozen plasma or cryoprecipitate in Iran, until 2009, when factor XIII concentrates became available for the treatment of patients. Several studies on the efficacy and safety of prophylactic regimes in different situations with valuable findings have been evaluated.Conclusion: This comprehensive study that covered all aspects of FXIII deficiency provided a suitable backbone for the diagnosis and management of FXIII deficiency in Iran.

Introduction: Factor XIII deficiency is a relatively rare hereditary bleeding disorder, which is usually found during infancy or early childhood. This condition may involve both genders within different races in an equal manner. Its incidence is estimated at approximately 1 in 106 live births. Patients with factor XIII deficiency are presented with a pattern of neonatal hemorrhage and lifelong bleeding diathesis.Case Presentation: A five-year-old female is presented here, who was diagnosed as a definite case of factor XIII deficiency, based on the clinical and laboratory findings at a medical specialist clinic. Typical clinical features of the disorder were the chief complaint of the patient, which was severe bleeding when she was brought into a specialized dental office following an earlier dental procedure.Conclusions: The case was fully investigated and diagnosed as a case with factor XIII deficiency causing such uncontrolled bleeding after extraction of a tooth.

Congenital factor XIII (FXIII) deficiency is an extremely rare bleeding disorder (RBD) with estimated prevalence of one per 2 million in the general population. The disorder causes different clinical manifestations such as intracranial hemorrhage (ICH), recurrent miscarriage, umbilical cord bleeding, etc. High incidence of the disorder might be due to founder effect. To assess founder effect, haplotype analysis is an important step. For this purpose, suitable and reliable genetic markers such as microsatellites (Hum FXIIIA01 and HumFXIIIA02) and single nucleotide polymorphisms (SNP) are suggested. In the present study we tried to describe evaluation of founder effect in patients with congenital FXIII deficiency via haplotype analysis using suitable genetic markers. . .