Factor XI deficiency is a congenital coagulation disorder seen primarily among Jews of Eastern European descent - Ashkenazi Jews.
It is inherited as an autosomal recessive and is the fourth most common coagulation disorder following von Willebrand's disease and haemophilia's A and B.
It is a mild bleeding disorder and usually manifests late in life or following dental or surgical procedures. The partial prothrombin time is prolonged markedly and specific assays of factor XI show reduced levels.
Specific factor XI concentrates may not be available but haemorrhage can usually be controlled by plasma infusion.
Last reviewed 01/2018