Authors' recommendations: Factor XI deficiency, also known as Rosenthal syndrome or hemophilia C, is an inherited blood coagulation disorder caused by deficiencies of clotting factor XI. Factor XI deficiency is rare in the general population, occurring with a frequency of 1:1,000,000; however, as symptoms can be relatively mild, prevalence may be greater than reported. The disorder is reported more frequently in ethnic groups such as French Basque and Ashkenazi Jewish populations, where prevalence is as high as 1:450. Symptoms of factor XI deficiency vary in severity and may include prolonged bleeding or oozing after injury, surgery, and tooth extraction. Areas with high fibrinolytic activity, such as the urogenital tract and nasal and oral cavities are most often affected; however, bleeding is rarely spontaneous. The role of factor XI in the clotting cascade is not entirely clear, but it is thought that factor XI is instrumental in activating other components of the clotting cascade, including those protective of newly formed blood clots. The severity of factor XI deficiency is often described according to the level of factor XI coagulation activity (FXI:C) in plasma, but this level does not necessarily correlate to bleeding tendency. Factor XI is encoded by the F11 gene, and genetic abnormalities (variants) in F11 lead to the development of disease. Close to 200 disease causing F11 variants have been reported, but commercial testing in the United States is only available for up to 4 of these variants. Two of the variants for which commercial testing is available account for up to 95% of factor XI deficiency in the Jewish population, and have been detected in other populations as well. Early reports defined factor XI deficiency as exhibiting an inheritance pattern of autosomal dominant with high penetrance; further study suggested that inheritance of factor XI deficiency more closely fits an autosomal, incompletely recessive model (i.e., individuals carrying one disease-causing variant may exhibit milder symptoms). The current standard of care for treatment of severe factor XI deficiency consists of administration of fresh frozen plasma, factor XI concentrates, or recombinant FVIIa (NovoSeven® RT; Novo Nordisk Inc.). Antifibrolytic agents such as tranexamic acid or epsilon aminocaproic acid may be administered prior to minor procedures.

Project Status: Completed

Year Published: 2011

URL for published report: http://www.hayesinc.com/hayes/crd/?crd=13081

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: HAYES, Inc.

Contact Address: 157 S. Broad Street, Suite 200, Lansdale, PA 19446, USA. Tel: 215 855 0615; Fax: 215 855 5218

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Contact Email: saleinfo@hayesinc.com

Copyright: 2011 Winifred S. Hayes, Inc