Factor XI deficiency

Classification according to ICD-10
D68	Other coagulopathies
ICD-10 online (WHO version 2019)

The Factor XI deficiency is an inherited or acquired bleeding disorder caused by the absence or deficiency of coagulation factor XI is caused (plasma thromboplastin antecedent, Rosenthal factor). It leads to an increased tendency to bleed (hemorrhagic diathesis), so that bleeding occurs more easily than in healthy people. The congenital or hereditary factor XI deficiency is also referred to as hemophilia C or Rosenthal syndrome (not to be confused with Rosenthal-Klöpfer syndrome ) and belongs to the group of hemophilia .

frequency

The congenital factor XI deficiency is a very rare disease overall. The worldwide incidence , i.e. the number of new cases per year, is estimated at one case per million people. The disease is far more common in Jewish population groups, especially the Ashkenazi Jews . It is estimated that 0.2 to 0.53 percent of Ashkenazi Jews are homozygous and 8 to 9% heterozygous carriers of gene mutations in the factor XI gene, so that congenital factor XI deficiency is one of the most common congenital diseases in this population group .

root cause

The congenital factor XI deficiency is caused either by gene mutations in the gene coding for factor XI or, much less often, by a complete deletion of the gene. The genetic defect is inherited as an autosomal and irregular recessive trait. The gene is located on the long arm of chromosome 4 (q arm). About 150 different mutations of this gene are known. The first mutations were published in 1989.

classification

According to the activity of factor XI in the blood and the genetic constellation, two degrees of severity of the disease can be distinguished. Normal activity is 70–150 percent (70 to 150 U / dL).

In the case of partial factor XI deficiency , the activity of factor XI is between 20 and 70 percent. Those affected have a heterozygous mutation in the factor XI gene. Occasionally, activity rates in heterozygous people are normal. In severe Factor XI deficiency, the Factor XI activity is below 15 percent. Homozygotes and compound heterozygotes suffer from this form of the disease .

Clinical picture

In the case of factor XI deficiency, the risk of bleeding is increased, especially after trauma , i.e. external violence, and accidents. However, factor XI activity only partially correlates with the risk of bleeding. Even with severe factor XI deficiency, the risk of developing spontaneous bleeding, joint (hemarthrosis) and muscle hemorrhage is not significantly increased compared to classic hemophilia A and B.

Individual evidence

1. ^ ^{A b} Caroline Bérubé: Factor XI deficiency . Uptodate version 16.1, as of February 2008.
2. ↑ International Society on Thrombosis and Haemostasis - mutations-databases: Mutations in patients with factor XI deficiency. Status 2007 online version ( memento of the original from September 6, 2008 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. 
3. ↑ R. Asakai et al.: Factor XI (plasma thromboplastin antecedent) deficiency in Ashkenazi Jews is a bleeding disorder that can result from three types of point mutations . In: Proc Natl Acad Sci U.S.A. 1989 Oct; 86 (20), pp. 7667-7671. PMID 2813350