Congenital Factor X Deficiency
Congenital factor X (FX) deficiency with an estimated incidence of 1:1,000,000 is one of the rarest and most severe bleeding disorders that is inherited in autosomal recessive manner. Acquired form of FX deficiency is also rare and usually occurs in relation with AL amyloidosis. The most frequent bleeding diathesis in FX deficiency is mucosal bleedings such as epistaxis, gum bleeding, easy bruising, and menorrhagia. Spontaneous major bleedings such as hemarthrosis, hematoma, gastrointestinal (GI) and central nervous system (CNS) bleeding usually occur in the severely affected individuals. The patients with less severe FX deficiency may bleed after hemostatic challenges including surgery or trauma. FX deficiency is suspected following abnormal bleeding history with prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT) that will correct with a 1:1 mix with normal plasma. Then diagnosis should be confirmed by specific tests including antigenic (FX:Ag) and functional (FX:C) assays. Treatment of FX deficiency is based on replacement therapy by fresh frozen plasma (FFP) and prothrombin complex concentrate (PCC). A single-factor FX concentrate produced from human plasma (pdFX) recently was approved by FDA.
KeywordsFactor X deficiency Bleeding disorder Diagnosis Mutation Treatment
- 4.Peyvandi F, Menegatti M. Inherited deficiencies of coagulation factors II, V, V+VIII, VII, X, XI, and XIII. In: Williams hematology. 9th ed. New York: McGraw-Hill; 2016. p. 40.Google Scholar
- 11.Palla R, Peyvandi F, Shapiro AD. Rare bleeding disorders: diagnosis and treatment. Blood. 2015. https://doi.org/10.1182/blood-2014-08-532820.
- 18.Vaidya K, Arnott C, Biscoe A, Eggleton S, Brighton T. Differential diagnosis and therapeutic limitations in a rare case of acquired factor X deficiency. Case Rep Intern Med. 2015;2(4):55.Google Scholar
- 21.Genotype of patients with factor X deficiency. 2011. http://c.ymcdn.com/sites/www.isth.org/resource/resmgr/publications/fx_mutations-2011.pdf?hhSearchTerms=%22coagulation+and+factor+and+X%22
- 25.Kaushansky K, Williams WJ, Joseph W. Williams hematology. New York: McGraw-Hill Medical; 2010.Google Scholar
- 31.io Products Laboratory Receives FDA approval for Coagadex® (Coagulation Factor X, Human). 2015. http://www.businesswire.com/news/home/20151021005989/en/Bio-Products-Laboratory-Receives-FDA-approval-Coagadex%C2%AE
- 32.FDA Approves Coagadex®. First factor X concentrate. 2015. https://www.hemophilia.org/Newsroom/Medical-News/FDA-Approves-Coagadex-First-Factor-X-Concentrate