factor XII deficiency

Factor XII Deficiency: A Rare Inherited Coagulation Disorder

Factor XII deficiency, also known as Hageman factor deficiency, is a rare inherited coagulation disorder that affects the production of factor XII (FXII), a plasma glycoprotein and clotting factor. This condition is characterized by an abnormal prolongation of blood clotting time in a test tube, but it does not cause excessive bleeding or clinical symptoms in affected individuals.

Key Features:

• Rare Inheritance: Factor XII deficiency is inherited in an autosomal recessive fashion, meaning both parents must carry the gene to pass it on to their children.
• Asymptomatic: Individuals with factor XII deficiency are usually asymptomatic and do not experience excessive bleeding, even after major surgical procedures or trauma.
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Factor XII deficiency, also known as Hageman factor deficiency, is a rare bleeding disorder that affects the production of coagulation factor XII (FXII). The signs and symptoms of this condition are relatively mild and often asymptomatic.

• Asymptomatic: Most individuals with factor XII deficiency do not experience any noticeable symptoms or bleeding episodes [1][3].
• Prolonged clotting time: When blood from a patient is subjected to a partial thromboplastin time (PTT) test, it takes an abnormally long time for the blood to clot [1].
• Normal PT and TT: The prothrombin time (PT) and thrombin time (TT) tests are usually normal in individuals with factor XII deficiency [6][15].

It's worth noting that factor XII deficiency is often discovered during routine screening or when clotting tests are performed for other reasons. In most cases, the condition does not cause excessive bleeding or any significant symptoms.

References: [1] Context result 1: Signs & Symptoms. [3] Context result 3: Factor XII (FXII) deficiency, also called Hageman factor deficiency... [6] Context result 6: Severe factor XII deficiency is characterized by a markedly prolonged PTT (>100 seconds) with normal PT, TT, and bleeding time. [15] Context result 15: Factor XII deficiency is most often found when clotting tests are done for routine screening.

Diagnostic Tests for Factor XII Deficiency

Factor XII deficiency, also known as Hageman factor deficiency, can be diagnosed through various blood tests that measure the activity of factor XII in the blood.

• Factor XII assay: This test measures the activity of factor XII and is used to confirm a diagnosis of factor XII deficiency. It is often performed along with other clotting tests.
• Partial thromboplastin time (PTT): This test measures how long it takes for blood to clot and can be prolonged in individuals with factor XII deficiency.
• Mixing study: A special PTT test that involves mixing the patient's plasma with normal plasma to see if the clotting time returns to normal. If the clotting time remains abnormal, it suggests a problem with factor XII.
• Activated Partial Thromboplastin Time (aPTT) Test: This test measures the time it takes for blood to clot and is used to evaluate the intrinsic pathway of coagulation, which is the pathway that factor XII is involved in.

These tests are often performed as part of routine screening for bleeding disorders or when an individual has a prolonged PTT result. A diagnosis of factor XII deficiency can be confirmed by a test called an assay, which measures the activity of factor XII in the blood [1][2].

References:

[1] Factor XII deficiency is most often found when clotting tests are done for routine screening. Tests may include: Factor XII assay to measure the activity of factor XII; Partial thromboplastin time to check how long it takes for blood to clot; Mixing study, a special PTT test to confirm factor XII deficiency [2].

[2] Some people with FXII deficiency experience poor wound healing. However, most do not display bleeding manifestations, even after major surgery. Testing. Since bleeding time is usually normal, diagnosis is made by a prolonged activated partial thromboplastin time (aPTT) test. A factor XII assay helps confirm the diagnosis [3].

[3] Factor XII deficiency is typically discovered during routine blood testing because reduced levels of factor XII cause the blood to take longer to clot [

Treatment for Factor XII Deficiency

Factor XII deficiency, also known as Hageman factor deficiency, is a rare genetic blood disorder that affects the production of clotting factor XII (FXII). While treatment is usually not necessary, there are some considerations to be aware of.

• No specific treatment: As mentioned in [5], no treatment is necessary for individuals with factor XII deficiency. This is because individuals with this condition are usually asymptomatic and form blood clots in vivo.
• Heparin anticoagulation: However, as noted in [6], heparin anticoagulation can be safely carried out with heparin concentration monitoring in patients with factor XII deficiency. This suggests that while treatment is not necessary for the condition itself, certain medical procedures may require special consideration.
• Fresh frozen plasma (FFP) transfusion: In some cases, as reported in [8], fresh frozen plasma (FFP) transfusion may be used to correct the activated partial thromboplastin time (aPTT) and other clotting parameters. However, this is not a standard treatment for factor XII deficiency.
• No excessive bleeding: It's worth noting that individuals with factor XII deficiency do not experience excessive bleeding, even after major surgical procedures or trauma [9]. This suggests that the condition does not pose a significant risk of bleeding complications.

In summary, while there is no specific treatment for factor XII deficiency, certain medical procedures may require special consideration. Individuals with this condition are usually asymptomatic and form blood clots in vivo, and do not experience excessive bleeding.

References:

[5] - No treatment is necessary for individuals with factor XII deficiency. [6] - Heparin anticoagulation can be safely carried out with heparin concentration monitoring in patients with factor XII deficiency. [8] - Fresh frozen plasma (FFP) transfusion may be used to correct the activated partial thromboplastin time (aPTT) and other clotting parameters. [9] - Individuals with factor XII deficiency do not experience excessive bleeding, even after major surgical procedures or trauma.

Differential Diagnosis of Factor XII Deficiency

Factor XII deficiency, also known as Hageman factor deficiency, is a rare bleeding disorder that can be challenging to diagnose due to its similarity with other conditions. The differential diagnosis for factor XII deficiency includes:

• Cryoglobulinemia: A condition characterized by the presence of abnormal proteins in the blood that can cause bleeding and clotting disorders.
• Disseminated Intravascular Coagulation (DIC): A serious disorder that causes widespread clotting in small blood vessels throughout the body, leading to bleeding and organ damage.
• Dysfibrinogenemia: A rare genetic disorder that affects the production of fibrinogen, a protein essential for blood clotting.
• Factor IX Deficiency (Hemophilia B): A bleeding disorder caused by a deficiency in factor IX, a protein necessary for blood clotting.

These conditions can present with similar symptoms to factor XII deficiency, such as prolonged bleeding and clotting disorders. Therefore, it is essential to perform thorough diagnostic tests and consider the patient's medical history and physical examination findings when making a differential diagnosis.

References:

• [3] Factor XII deficiency is an inherited disorder that affects a protein (factor XII) involved in blood clotting.
• [4] Mar 18, 2024 — Differential Diagnoses · Cryoglobulinemia · Disseminated Intravascular Coagulation (DIC) · Dysfibrinogenemia · Factor IX Deficiency (Hemophilia B).
• [8] Sep 22, 2020 — Differential diagnosis. Acquired factor XII deficiency: associated with nephrotic syndrome, liver transplantation, autoimmune disease; Factor ...
• [11] Key differential diagnoses: Prothrombin time (PT) Factor deficiency or inhibitor (VII, X, V, II) Warfarin Vitamin K deficiency Liver disease Direct Xa inhibitor Activated partial ... Deficiency of contact factors (factor XII, prekallikrein, high molecular weight kininogen)
• [12] Factor XII deficiency is a deficiency in the production of factor XII ... Other rare forms of bleeding disorders are also in the differential diagnosis.