Factor XIII Deficiency.
Factor XIII (FXIII) is a tetrameric zymogen (FXIII-A (2)B (2)) that is converted into an active transglutaminase (FXIIIa) by thrombin and Ca (2+) in the terminal phase of the clotting cascade. By cross-linking fibrin chains and alpha (2) plasmin inhibitor to fibrin, FXIIIa mechanically stabilizes fibrin and protects it from fibrinolysis. Severe deficiency of the potentially active A subunit (FXIII-A) is a rare but severe hemorrhagic diathesis. Delayed umbilical stump bleeding is characteristic, and subcutaneous, intramuscular, and intracranial bleeding occurs with a relatively high frequency in nonsupplemented patients. In addition, impaired wound healing and spontaneous abortion in women are also features of FXIII deficiency. The extremely rare B subunit deficiency results in milder bleeding symptoms. FXIII concentrate is now available for on-demand treatment and primary prophylaxis. A quantitative FXIII activity assay is recommended as a screening test for the diagnosis of FXIII deficiency. For classification purposes, FXIII-A (2)B (2) antigen in the plasma is first determined, and if decreased, further measurement of the individual subunits is recommended in the plasma and FXIII-A in platelet lysate. Analytical aspects of FXIII activity and antigen assays are discussed in this article. There are no hot-spot mutations in the F13A1 and F13B genes, and the majority of causative mutations are missense/nonsense point mutations.
Karimi
Mehran
M
Hematology Research Center, Nemazee Hospital, Shiraz University of Medical Sciences, Shiraz, Iran. Karimim@sums.ac.ir
Bereczky
Zsuzsanna
Z
Cohan
Nader
N
Muszbek
László
L
D000641:Ammonia / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005176:Factor XIII / Q000032:analysis / Q000235:genetics* / Q000502:physiology; D005177:Factor XIII Deficiency / Q000235:genetics* / Q000628:therapy; D005260:Female; D005341:Fibrinolysin / Q000627:therapeutic use; D005838:Genotype; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D010641:Phenotype; D006473:Postpartum Hemorrhage / Q000517:prevention & control; D011247:Pregnancy
D000641:Ammonia; D005176:Factor XIII; C054380:factor XIIIb; D005969:Glutamate Dehydrogenase; C061421:glutamate dehydrogenase (NAD(P)+); D005341:Fibrinolysin