I had never heard of Factor V Leiden until almost two years ago. I received a phone call one morning, my mother told me that my sister, 30 at the time, had been admitted into the hospital. We did not know what had happened to her, but she was unresponsive to her husband, so he called the paramedics and they took her in.
She got transferred from one hospital to another, finally starting to come around, however she was not speaking. It was a nightmare to see her in the hospital barely able to communicate with me. She could understand everything I was saying to her, but she could not communicate properly in reply. It’s as if her body was unable to produce her thoughts into words, orally or written. We later learned that she had a stroke.
After a week in the hospital, therapy, and several tests to determine the cause, it was discovered that my sister has Factor V Leiden. My mother and father got tested, along with my four other sisters and myself. My father and four of us girls (including myself) all have Factor V Leiden. Any one of us could have had that stroke.
Before going into what Factor V Leiden is, let me first talk about blood clots (thrombi). Blood clots normally form to stop bleeding when a vein or artery is damaged (getting a cut for example). Chemical reactions between platelets and clotting factors (proteins) in your blood form blood clots. We have anti-clotting factors to control an excessive formation of blood clots.
Coagulation Factor V is one clotting protein, made by the F5 gene that reacts with the platelets in our blood. The F5 gene plays a very important role in the formation of blood clots due to injury. People with Factor V Leiden have a genetic mutation in the F5 gene that causes the Factor V protein to respond more slowly to the anti-clotting factors.
Activated protein C (APC) is a molecule that inactivates the Factor V protein in an effort to prevent blood clots from growing too large. For those with Factor V Leiden, APC is unable to inactivate the Factor V protein normally, increasing the risk of developing abnormal blood clots.
Factor V Leiden is an inherited genetic disorder, resulting in a higher risk of developing blood clots (thrombosis), usually in the veins rather than arteries. This gene mutation is passed on by one or both parents, but only if they have the disorder as well. Your parents either pass on two normal genes, one normal and one mutated gene (heterozygous), or two mutated genes (homozygous). Factor V Leiden is the most common form of Thrombophilia (an inherited tendency to form blood clots). Between 3-8% of Caucasians in the US and Europe are heterozygous for Factor V Leiden. About one in 5,000 people are homozygous for Factor V Leiden. This gene mutation is less common in other races. What does this mean for you?
If your parents have passed on two normal genes, you have nothing to worry about regarding Factor V Leiden, however, that doesn’t mean that you cannot form abnormal blood clots. Blood clots can form at any age, however, for most people the increased risk of clotting doesn’t begin until adulthood. For the general population, the risk of developing an abnormal blood clot averages to be about 0.1% per year. For those heterozygous for Factor V Leiden, the risk increases to be about 0.4-0.8% per year. For those homozygous for Factor V Leiden, the risk can be as high as 8.0% per year.
Most people with Factor V Leiden do not develop abnormal clots, however, some do that can lead to long-term health problems or can be life-threatening. The combination of Factor V Leiden and other gene mutations involved in blood clotting can also influence your risk of abnormal clotting. Men and women alike can have Factor V Leiden, but women may have an increased risk to develop blood clots during pregnancy or by taking the Estrogen hormone.
If you are unsure if you have Factor V Leiden, you should see a doctor if:
• Any of your family members have Factor V Leiden.
• Your family has a history of blood clots.
• You’ve had one or more clotting incidences with no apparent cause.
• You are female and have had repeated miscarriages or unexplained pregnancy complications.
• If you develop signs or symptoms of deep vein thrombosis (DVT) such as leg pain and swelling.
• If you develop signs or symptoms of a pulmonary embolism, such as chest pain or discomfort.
If you have already been diagnosed with Factor V Leiden, you should take extra care in avoiding situations that may increase your risk of blood clotting. Some situations include:
• Sitting for long periods of time (long car or airplane rides) – Make sure to get up periodically and walk around, even if it’s just for a minute or two.
• Prolonged bed-rest (during long illness, paralysis, or pregnancy complications) – When your legs remain still for long periods, your calf muscles don’t contract to help blood circulate.
• Injury or surgery – Injury to your veins or surgery can cause your blood flow to slow down, which increases the risk of forming blood clots. General anesthetics used during surgery can dilate your veins which can also increase the risk of forming blood clots.
• Oral contraceptives and Estrogen replacement therapy – Discuss the risks and benefits of estrogen-containing medications with your doctor.
• Obesity – Being overweight increases the pressure in the veins in your pelvis and legs.
• Smoking – Smoking affects circulation and blood clotting.
If you are a woman who has Factor V Leiden, please check with your doctor for any precautions necessary during pregnancy. Most women with Factor V Leiden have normal pregnancies, but this gene mutation has been linked with miscarriage and possibly preeclampsia, slow fetal growth, and early separation of the placenta from the uterine wall. Make sure your doctor is aware you have Factor V Leiden so that he/she can monitor you closely throughout your pregnancy.
My sister has almost fully recovered from her stroke. She still has some speech problems, a difficulty reading out loud to her children at times, and she can no longer type as fast as before. She takes medication daily to help lower the risk of forming more clots. There’s no way to say if her stroke could have been prevented if she had known she had Factor V Leiden, but now those of us that do have it can be more careful ourselves.
Resources:
NetDoctor
Genetics Home Reference
MayoClinic.com
