VPB0721 - A Rare Case of Factor XII Deficiency Manifesting as bleeding disorder

Background: Factor XII, also known as Hageman factor, is a plasma serine protease implied in the intrinsic pathway of coagulation. FXII deficiency is a rare, autosomal recessive disorder, with an incidence of approximately 1 in a million. Asymptomatic prolongation of aPTT is the most commonly reported manifestation of factor XII deficiency, and it is very rarely associated with bleeding diathesis and hemorrhage.

Aims: The aim of this case report is to describe a rare case of unusual bleeding secondary to Factor XII deficiency in an adult patient.

Methods: A 30-years-algerian female patient presented following a history of abundant hemorrhage after surgical intervention for wisdom tooth removal, no other history of bleeding was described and her general physical examination was unremarkable.

Results: Laboratory investigation showed normal complete blood count, liver functions and serum electrolytes were normal. Baseline coagulation studies showed isolated prolonged aPTT = 64s. Absence of any inhibitors with a correction of mixing test after incubation at 37oC. Coagulation factor assay panel for intrinsic pathway showed deficiency of factor XII being 2%. No other coagulation abnormality was detected. Hemorrhagic manifestations caused by FXII deficiency are rarely described in the literature. Theoretically, FXII deficiency may lead either bleeding risk or a risk of thrombosis. Bleeding caused by FXII deficiency, if described, is very mild, such as epistaxis or skin abrasions. In our case, we were able to link the bleeding disorder to the factor XII deficiency.

Conclusion(s): FXII deficiency is a rare disorder, treatment for this disorder is usually not necessary since bleeding abnormalities are only mild or nonexistent.