Factor XIII Deficiency

Factor XIII deficiency is an extremely rare factor deficiency, with an estimated incidence of 1 in 5 million births. It is inherited in an autosomal recessive fashion, meaning it is equally likely to affect men and women. The deficiency affects no racial or ethnic group disproportionately.

Factor XIII is a protein found in plasma and is present in platelets, monocytes, and macrophages. In addition, Factor XIII consists of two A-subunits and two B-subunits, and is integral in helping the body during coagulation by protecting against the breakdown of fibrin, the molecule that forms the framework of a clot. In the absence of factor XIII, a clot will still develop, but it will be unstable. When someone has factor XIII deficiency, the unstable, non-cross linked clot will eventually break down, so delayed bleeds are common. The persistent bleeding seen with factor XIII deficiency usually occurs associated with trauma.

Patients with a severe form of factor XIII deficiency have a high risk of intracranial bleeds with or without trauma. Bleeding immediately after surgery is usually not excessive but can be persistent when it begins after a delay. Pregnant women deficient in factor XIII who go untreated face an increased risk of spontaneous abortion. Men with the deficiency may have problems with fertility. Common signs of the deficiency include soft tissue bleeds, menorrhagia, joint bleeding and persistent bleeding during circumcision or at the site of the umbilical cord.

Specific factor XIII assays can be employed to confirm the diagnosis. The condition can also be defined by a clot urea solubility test.