Mutation of prothrombin (factor II)

General Information

Coagulation factor II or prothrombin is a plasma glycoprotein that is an important factor in the clotting process. It exists in two forms in plasma: "closed" (80%) and "open" (20%).

Factor II (prothrombin) deficiency can be congenital or acquired. Acquired deficiency is caused by specific diseases, medications, or autoimmune processes. The most common cause of prothrombin deficiency is:

• Vitamin K deficiency
• Liver diseases
• Long-term treatment with anticoagulants
• Autoimmune inhibitors (antibodies) that inhibit clotting processes.

Hereditary deficiency is very rare. It is caused by a mutation in the factor II gene.

A mutation of the prothrombin gene (that is, factor II) is a genetic pathology that increases the probability of the formation of abnormal blood clots in the veins (deep vein thrombosis) and in the lungs (pulmonary embolism).

A mutation in the factor II gene can be inherited from one or both parents. If an individual receives a pathological (mutated) copy of a gene from one parent, a heterozygous condition develops, and in case of inheritance from both parents, a homozygous condition develops.

What is the frequency of the disease?

50 out of 1 people in Europe and North America is heterozygous for a mutation in the prothrombin gene (that is, their genotype contains 1 mutated copy of the prothrombin gene).

The risk of thrombosis in heterozygous individuals is 3 times higher than in individuals with a normal factor II gene.

After Leiden factor V, prothrombin (factor II) gene mutation is the second most common cause of hereditary thrombophilia, occurring in 20% of cases. This mutation was confirmed in patients with idiopathic thrombosis of portal vein and cranial sinus veins, taking oral contraceptives and in cases of pregnancy complications.

Symptoms

Factor II deficiency symptoms are:

Bleeding from the umbilical cord at birth

Causeless bruises

Prolonged bleeding after any wound, including surgical intervention

Bleeding from the nose and gums

Prolonged menstrual bleeding

Internal bleeding - in tissues and organs

Diagnosis

Factor 2 gene mutation is suspected if:

• 2 or more episodes of thrombosis in the past
• If the patient develops thrombosis at a young age without any other cardiovascular pathology
• If there is a family history of thrombosis

Laboratory diagnostics is based on:

• to limit the various factors of coagulation
• determination of factor II in serum
• Determination of PT prothrombin time is estimated by determination of factors I, II, V, VII and X during clotting.
• PTT partial thromboplastin time – determines the clotting time by estimating factors VIII, IX, X, XII and Willebrand.

Study material: Venous blood

Reference norm: 70-120%