Tonsillectomy Uncovers a Genetic Predisposition for Blood Clots

Eighteen-year-old Caitlin Augustine found herself in the hospital right before Christmas about four years ago for a routine tonsillectomy. The surgery was uneventful and Caitlin was at home resting on the couch when her left leg started to bother her. She thought that maybe she pulled a muscle from sleeping on the couch.

After a week, the pain became so intense that she could not move. Her doctor thought she might have contracted a bladder infection and sent her home with antibiotics. When that treatment failed, she found herself back at the doctor's office, where a CT scan revealed a blood clot in her left iliac vein that stretched from her knee to the major blood vessel that returns blood to the heart, the inferior vena cava. She was seen by a hematologist and treated with blood-thinning medications.

Caitlin's hematologist investigated why such a young, healthy woman would have a blood clot. Some tests revealed that she tested positive for factor V Leiden (lye-den), an inherited disorder of blood clotting.

What Is Factor V Leiden?
According to the Surgeon General, factor V Leiden is a relatively common genetic disposition that increases the risk for blood clots or deep vein thrombosis (DVT), blood clots that form in the deep veins, usually of the legs. An estimated 15-20 percent of patients with DVT or pulmonary embolism (PE) have this gene, which is most commonly found in Caucasians.

After Caitlin tested positive for factor V Leiden, other members of her family were tested and the results revealed that several relatives on her father's side of the family also carry the gene. One of Caitlin's uncles, who also tested positive, suffered blood clots when he was younger while working on a construction site.

Caitlin is one of five percent of Caucasians who have the genetic risk for the gene mutation, factor V Leiden. The more risk factors a patient has, the greater the risk for DVT. In Caitlin's case, she had three risk factors that caused her blood to clot at such a young age.

Not only did Caitlin test positive for the genetic mutation that put her at higher risk for blood clots, but her recent surgery and the fact that she had been taking birth control pills for ovarian cysts for the past three years also increased her risk. One risk factor gives an individual a three-fold increase in the risk of clotting; if a person has two risk factors, then he or she is at 15-20 times greater risk. In Caitlin's case, she had three combined risk factors that put her at very high risk for DVT.

Please see this article for more information on DVT and genetic clotting disorders.

What Is DVT?
Deep vein thrombosis (DVT) occurs when a blood clot, or thrombus, usually develops in the large veins of the legs or pelvic area, or less commonly in the arms. Only half of those with DVT will have typical symptoms of leg swelling and pain. With prompt diagnosis and treatment, the majority of DVTs are not life threatening. However, if the blood clot breaks loose and travels through the heart to the lung arteries, a condition known as a pulmonary embolism (PE) occurs. If the traveling clot, called an embolus, clogs the main lung artery, it can be fatal.

"I was in a constant state of worry that I would have a PE and would wake up with panic attacks that something would go wrong," said Caitlin. "The quality of my life has changed radically. My leg swells up easily and I have constant leg pain even when I try to do little things."

Although she did not have a PE, the clot is now calcified and cannot be removed. While not everyone requires lifelong anticoagulation medication, Caitlin will be dependent upon the blood thinner, warfarin, for the rest of her life. She has also developed post-thrombotic syndrome (PTS), which is a long-term complication of DVT that causes chronic pain and swelling in the leg. Her leg swells up and is painful even from minor activities such as walking her dog, Casey. It prevents her from participating in many normal activities for a young woman her age.

This past year, Caitlin experienced another DVT in her right arm and has also tested positive for the lupus anticoagulant which is also associated with an increased risk for DVT. This acquired clotting disorder is generally not inherited like the factor V Leiden. Unfortunately, the combination of the lupus anticoagulant and factor V Leiden significantly increases the risk of future venous thrombotic events. For this reason, it has been recommended that she continue indefinitely the anticoagulation therapy with warfarin.

Despite all of Caitlin's health challenges, she continues to find ways to educate others about DVT. She has participated in numerous health fairs at her college and volunteers for VDF's Venous Disease Coalition to share her experience and alert others about the symptoms and risk factors for DVT. Next year, she hopes to pursue a degree in health communications.

"Many people assume that DVT affects only older people," said Caitlin. "I want everyone to know that your age does not matter when it comes to DVT. What matters are your risk factors and how many you have at any given time."