Factor XIII deficiency

Factor XIII deficiency occurs exceedingly rarely, causing a severe bleeding tendency. The incidence is one in a million to one in five million people, with higher incidence in areas with consanguineous marriage such as Iran that has the highest global incidence of the disorder. Most are due to mutations in the A subunit gene (located on chromosome 6p25-p24). This mutation is inherited in an autosomal recessive fashion.
Deficiency of Factor XIII leads to defective cross-linking of fibrin and vulnerability to late re-bleeds when the primary hemostatic plug is overwhelmed. Bleeding tendencies similar to hemophiliacs develop, such as hemarthroses and deep tissue bleeding.
As Factor XIII is composed of two subunit protein, A and B, for which the genes are located on different chromosomes, administration of recombinant A subunit improves clot stability and is becoming a therapeutic option for patients with this condition.