Factor XII deficiency is a rare disorder, featuring a pathologically reduced concentration of the coagulation factor XII in the serum. Factor XII, also referred to as Hageman factor, is a plasma protein that contributes to the initiation of the intrinsic coagulation cascade.
Factor XII is a plasma protein that is involved in the initiation of the intrinsic coagulation cascade. In the majority of cases, patients remain asymptomatic, with the only pathologic finding being the prolonged activated partial thromboplastin time (aPTT) detected via laboratory testing   .
Paradoxically, there is an absence of the hemorrhagic events usually associated with the deficiency of a coagulation factor. Moreover, propensity toward thrombotic events have been reported in patients with factor XII deficiency  . Even if clear pathophysiologic association has not yet been defined, studies have delineated the potential correlation between factor XII deficiency and the development of deep venous thrombosis (DVT) and other acquired thrombotic disorders. Unexplained miscarriages have also been observed in women affected by the deficiency . It should also be noted that the levels of circulating factor XII do not clearly correlate with the symptoms experienced by the patient or the severity of the disease. Furthermore, the concentration of factor XII in the serum of a patient varies, depending on each case.
Entire Body System
A patient with factor XII deficiency, gout, and angioimmunoblastic lymphadenopathy (AIL) was seen initially for an acute myocardial infarction, gout, and unexplained urticaria. [ncbi.nlm.nih.gov]
Factor XII deficiency in a man with gout and angioimmunoblastic lymphadenopathy. Arch Intern Med 1984; 144: 1497-8. 18 Penny WJ, Colvin BT, Brooks N. Myocardial infarction with normal coronary arteries and factor XII deficiency. [doi.org]
Soft Tissue Mass
She was reevaluated with magnetic resonance imaging, which showed dense infiltrative areas around knee and ankle joints, and computed tomography that showed a soft tissue mass surrounding the descending aorta and upper part of the abdominal aorta. [ncbi.nlm.nih.gov]
She was initially diagnosed with pharyngitis and inadvertently had blood cultures sent as part of her workup. [ncbi.nlm.nih.gov]
Aspiration of synovial fluid from his inflamed knee disclosed urate crystals and abundant leukocytes but an absence of Hageman factor antigen. [ncbi.nlm.nih.gov]
The following case report describes a previously healthy adult woman who presented with sore throat, left ear pain, and fever. She was initially diagnosed with pharyngitis and inadvertently had blood cultures sent as part of her workup. [ncbi.nlm.nih.gov]
Jaw & Teeth
Individuals affected by factor XII deficiency are primarily asymptomatic. A routine blood test or one carried out due to unrelated symptoms and conditions will reveal pathologic results that lead to the diagnosis of the disorder.
Finding consistent with factor XII deficiency include a prolonged activated partial thromboplastin time which indicates coagulation impairment of the intrinsic coagulation pathway. The normal aPTT values are between 30 and 50 seconds; a prolonged time required for blood clots to form indicates various clotting pathologies, one of which is factor XII deficiency. Serum prothrombin time (PT), which is used to evaluate the extrinsic pathway of coagulation, is within normal reference values in factor XII deficiency.
Differential diagnosis includes antiphospholipid syndrome . The definitive diagnosis of factor XII deficiency is established with a specific factor XII assay, that can reliably detect the activity of this coagulation factor.
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- Ganguli P, Rigvardhan and Kotwal, J. Thrombosis: Presentation of a Factor XII Deficiency in 10 Months Old Child—A Rare Case. International Journal of Advances in Case Reports. 2015;2:708-710.
- Ozgu-Erdinc AS, Togrul C, Aktulay A, Buyukkagnici U, Yapar Eyi EG, Erkaya S. Factor XII (Hageman) levels in women with recurrent pregnancy loss. J Pregnancy. 2014;2014:459192.
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