Factor V – Leiden mutation

General Information

Thrombophilia is a condition caused by congenital or acquired pathologies, during which the ability of blood to clot increases. Clinical manifestations of thrombophilia are: thromboembolic disease, repeated spontaneous abortions, pregnancy complications (eclampsia, preeclampsia, fetal growth retardation, placental apoplexy, stillbirth, premature birth), acute coronary syndrome, aseptic necrosis of the femoral head.

Almost half of cases of hereditary thrombophilia are due to factor V and prothrombin gene G20210a mutation.

Factor V Leiden mutation is an abnormal variant of factor V that is resistant to activated protein C. It is the result of a point mutation that occurs in the long arm of the first chromosome. The resulting factor V is called the Leyden factor. As a result of this mutation, Leiden factor V activity decreases 10 times compared to the norm and persists (delays) in the blood stream, which increases the risk of blood clots.

The mutation is transmitted in an autosomal codominant way (both alleles (copy) of the gene equally exhibit the properties and synthesize the characteristic protein) and the incidence of genetic thrombophilia is the cause of 3-7%.

The risk of thrombosis depends on whether the individual is homozygous or heterozygous for the mutation. In heterozygous individuals, compared to normal factor V, the risk increases by 4-8 times, and in homozygotes by 80-100-fold.

The risk of thrombosis is further increased by the coexistence of pathologies of other coagulation factors: protein c, protein s deficiency, MTHFR gene mutation (associated with hyperhomocysteinemia), oral contraception, pregnancy and others.

Study material: Venous blood

Method: PCR - real-time (by real-time detection of accumulated PCR material), genotyping at the end of the study.

Interpretation:

1. Homozygous wild type (no Leiden mutation)
2. Heterozygous genotype (contains wild-type healthy and mutated alleles)
3. Homozygous mutated genotype (contains both mutated alleles)