What is Factor-V?
Blood clotting is a multi-step process which involves many proteins. Factor V is one of such protein. This protein is also known as labile factor, and which is derived from liver and platelets. Factor-V helps in the conversation of prothrombin to thrombin which is one of the vital steps in the blood clotting cascade.
Difference between Factor-V and Factor-V Leiden
Factor-V is one of the proteins involved in blood clotting and Factor-V Leiden is the mutation or gene change which produces in the abnormal blood clots.
Factor-V Leiden
This is a genetic disorder, and which develops abnormal clots (thrombosis) mostly in legs called deep vein thrombosis (DVT). If this clot moves to lung through bloodstream and blocks the blood flow in lung, this condition is called as pulmonary embolism (PE) which is a lethal condition.
The clotting activity of Factor-V is controlled by activated protein C (APC), which turn off Factor-V to prevent blood clotting. But APC cannot work with Factor-V Leiden which lead to abnormal blood clotting. Hence, this Factor-V Leiden is also known as APC resistance. Factor-V Leiden mutation results from the G to A transition in 1601 position of nucleotide (c.1601G>A). This transition results in arginine to glutamine substitution (p.Arg534Gln) at amino acid 534 of protein.
Diagnosis of Factor-V Leiden
If you have a family history of thrombosis or if you are experiencing unnecessary blood clots or to know the inherited risk of having this mutation or if you are having DVT during pregnancy, the doctor suggests getting tested for Factor-V mutation. A simple blood test can be done by polymerase chain reaction to find out the mutation.
Genetics in Factor-V Leiden
This is an autosomal dominant disorder means one copy of the mutated gene can cause the increased risk of thrombosis.
- Factor-V Leiden heterozygous condition (GA, one variant) - having one mutated gene inherited from one parent and one normal gene from another parent.
- Factor-V Leiden homozygous condition (AA, two variants) - having two mutated gene inherited from both parents. No normal factor-V gene is present.
- GG, Leiden mutation is absent.
Heterozygous condition increases the risk of developing abnormal clots whereas having homozygous condition makes the situation worse means higher the chances of producing clots.
References
- Factor V Leiden - Symptoms and causes. (2020, August 1). Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/factor-v-leiden/symptoms-causes/syc-20372423#:%7E:text=Factor%20V%20Leiden%20(FAK%2Dtur,Leiden%20never%20develop%20abnormal%20clots.
- Kirshman, M. (2019, November 22). Factor V Leiden Mutation and PT 20210 Mutation. Testing.Com. https://www.testing.com/tests/factor-v-leiden-mutation-and-pt-20210-mutation/.
- Hanna Rennert PhD, Robert A. DeSimone MD, in Transfusion Medicine and Hemostasis (Third Edition), 2019
Hope this information helps you!
