Molecular testing for thrombophilia

Thrombophilia is an abnormality of blood coagulation. Patients with thrombophilia are more likely to develop blood clots.

Blood clots can lead to various complications throughout the human lifetime, severity of which depends on the size of the blood clot and the location of the blood vessel. Hereditary thrombophilia increases risk of a heart attack, apoplectic attack and development of pulmonary embolism, as well as lead to complications during pregnancy. For some patients, thrombophilia can be present without any clinical manifestations or complications, therefore hereditary thrombophilia cannot always be diagnosed based solely on the family medical history.

Increased blood coagulation can be caused by specific gene mutations. Factor V Leiden is the name of a specific gene (F5) mutation that results in thrombophilia. Prothrombin gene (F2) mutation also plays an important part in the development of thrombophilia. Presence of the aforementioned mutations increases the risk of thrombosis, and carriers of these gene mutations are subject to complications during pregnancy (habitual miscarriage, delayed or stalled prenatal development).

Complications during pregnancy or miscarriage can be linked to elevated homocysteine levels. As the elevated homocysteine levels damage blood vessel walls, the affected areas are prone to blood clots and accumulation of excess cholesterol, which facilitates blood vessel blockage. Abnormally high homocysteine level (hyperhomocysteinemia) may increase the risk of vascular thrombosis. Elevated homocysteine levels are associated with low levels of vitamin B, however more often than not it is caused by decreased MTHFR enzyme activity (changes in the MTHFR gene), which is of great importance in the homocysteine metabolism.

Research shows that during pregnancy thrombophilic predisposition can lead to a prothrombic state. It can alter blood circulation between the mother and the foetus, negatively impacting placentation processes, as well as interfere with normal embryonic development.

Patients with incomplete pregnancy, miscarriage, as well as complications related to the placenta, placental abruption and preeclampsia in anamnesis, are advised to undergo molecular tests for thrombophilia in order to control the condition and eliminate any possible risks.

Genetic centre iVF Riga offers tests on six mutations related to thrombophilic pathogenesis found in F5, F2 and MTHFR genes.

Plasminogen activator inhibitor (PAI) analysis is recommended for an in depth testing of hereditary thrombophilic predisposition.

As blood clots form in the human body, the protein system starts working and degrading them. The blood clot formation and degradation process has to be balanced, as abnormal blood coagulation can lead to thrombophilia, while disrupted blood clotting can cause bleeding disorders. PAI slows down the plasminogen conversion into plasmin, which degrades the fibrin in a blood clot and ultimately destroys it. Usually the PAI protein ensures gradual degradation of blood clots. If there have been changes in the regulatory region of the gene, the concentration of PAI protein in blood increases, thus interfering with the normal blood clot degradation process, which in turn leads to a higher risk of thrombosis.

Complications associated with thrombophilia, especially in pregnant women, can be prevented by medical therapy. Medical therapy is prescribed by the attending physician, taking into account family medical history, blood work and results of molecular testing. Timely diagnosis of thrombophilia can notably improve the chances of a successful pregnancy and a healthy baby.