Haemophilia : the official journal of the World Federation of Hemophilia
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Case Reports
Factor XIII deficiency: complete phenotypic characterization of two cases with novel causative mutations.
Coagulation factor XIII (FXIII) exists as heterotetramer (FXIII-A₂B₂) in the plasma and as dimer (FXIII-A₂) in cells. Activated FXIII mechanically stabilizes fibrin and protects it from fibrinolysis by cross-linking fibrin chains and α₂-plasmin inhibitor to fibrin. FXIII is essential to maintaining haemostasis, and its deficiency causes severe bleeding diathesis. ⋯ Proband2 was homozygote for a novel single nucleotide deletion (c.212delA) leading to early stop codon. The discovered mutations explain the severity of clinical symptoms and the laboratory data. Methods precise in the low activity/antigen range are required to draw valid conclusion on phenotype-genotype relationship.