Factor V Leiden is a blood clotting disorder. It is not a disease. Factor V is a protein that is needed for blood to clot properly. Some people do not have the normal Factor V protein. Instead, they have an different form called Factor V Leiden. This is caused by a change (mutation) in the gene for this protein. The different gene that makes the Factor V Leiden protein is inherited from one or both parents.The Factor V Leiden protein is harder to “turn off” than the normal Factor V protein. This makes blood clots more likely to form, a condition called thrombophilia.Most people who have factor V Leiden never develop signs or symptoms. The first indication that you have the disorder may be the development of a blood clot (thrombosis). Deep vein thrombosis may not cause any symptoms.
Warmth A blood test (called a screening test) can show if one have Activated Protein C resistance. Another blood test that examines your genes (called DNA) will be done to find out if Factor V Leiden is the cause of the resistance and what type of Factor V Leiden you have. Some hospitals do only the DNA test and not the screening test. Having Factor V Leiden means that you have a greater chance of developing a dangerous blood clot in your legs (DVT) or lungs (PE). About 1 out of 10,000 people will develop a DVT or PE each year.
• by age 80, this risk is 1 in 100 per year