Diagnosis of the 20210G A mutation of the F2 prothrombin gene (c. 97G A)

Diagnosis of the 20210G>A mutation of the prothrombin F2 gene (c.*97G>A)

Clinical significance

Virchial thrombosis is a serious health problem, affecting 1:1,000 peopleób per year. Coagulation of blood in blood vessels is possible due to a slowing down of blood flow, damage to the blood vessel wall or an increase in blood clotting (Virchow's triad). There are numerous external factors conducive to thrombosis, including immobilization (after surgery, due to bedridden illnesses, on a long commute), cardiac arrhythmias (especially atrial fibrillation), cancer, age over 60, hormone therapy in women, pregnancy and puerperium, obesity and lipid disorders, lower limb varicose veins, intravascular manipulation (catheterization, venflon). There is also a known propensity for genetically determined increased blood clotting, caused by common polymorphic variants of genów: prothrombin (F2) on chromosome 11p11 (a variant in the non-coding region of 20110G>A) in 1-5% of the European population, the proacellarin gene (F5) on chromosome 1q23 (1691G>A, a Leiden-type mutation) in 10-15% of the European population (25% of all casesóThrombophilia and 50% of familial cases) and methylenetetrahydrofolate reductase (MTHFR) on chromosome 1p36 (thermolabile variants 677C>T and 1298A>C) in 30-40% of the European population. Inheritance of propensity to thrombosis dominant, more frequent symptoms in women. Thrombosis susceptibility is usually asymptomatic, with probably 90-95% of carriers having no symptomsów before age 50. Typical concerns are venous thrombosis (in the deep veins of the extremities) and pulmonary embolism occurring at any time in life, ogó³ with the presence of multiple risk factors. Sometimes a less typical localization is observed, such as veins of the mógovt, liver, abdominal cavity, reticular or arterial vessels. The presence of one mutation increases the risk of a thrombotic episode by about 5-fold in adults and about 3-fold in children. If more than one mutation is present, the risk of thrombosis multiplies. Recurrence of thrombosis is observed in 1/4 -1/3 of patients, usually within a few years, and there is a clear risk of a repeat episode in pregnant women whoóve previously had thrombotic symptoms. In addition, women who carry the mutation have an independent risk of spontaneous abortions (after 10 weeks), a hypertrophic state, placental detachment, intrauterine fetal growth retardation, with symptoms in about 10% of women, unrelated to venous thrombosis. In homozygotes, symptoms are of similar severity, usually occur earlier, but the risk of symptomsów is many times greater.Indications for the test are: - diagnosis of cases of venous thrombosis, especially unprovoked before the age of 50 or recurrent cases of venous thrombosis or thrombosis of unusual location or thrombosis associated with hormonal disorders (pregnancy, puerperium, use of estrogenóg in replacement therapy or contraception);- diagnosis of cases of reproductive failure, especially recurrent miscarriages after 10 weeks, severe casesóof pre-eclampsia, placental detachment or severe intrauterine growth retardation and some congenital malformations;- diagnosis of casesóof "isolated" pulmonary embolism and casesóof myocardial infarction or stroke in smoking women before the age of 50.age;- family testing: detection of F2, F5, or MTHFR gene mutations in a relative in families with symptomatic thrombosis before age 50. It is advisable to test asymptomatic siblings of the carrier, especially before planned surgeries, and women related to the carrier before planned pregnancy or planned estrogenów.The test is available in 4 variants, usually used sequentially:- analysis of Leiden mutations in the F5 gene (1st-line test);- analysis of Leiden mutations in the F5 gene and 20210G>A mutations in the F2 gene (2nd-line test);- analysis of 677C>T mutations (p.A222V) and 1298A>C (p.E429A) mutations in the MTHFR gene (3rd-line test, recommended especially in cases of elevated blood homocysteine levels);- analysis of Leiden mutations in the F5 gene, 20210G>A mutations in the F2 gene, and 677C>T and 1298A>C mutations in the MTHFR gene (4th-line test, interchangeable with the previous variantsów).

Patient preparation

no special recommendations

Material: EDTA blood

Interventions

none