Clotting disorders is a term used to describe a group of conditions in which there is an increased tendency, often repeated and over an extended period of time, for excessive clotting.

These disorders include inherited conditions such as Factor V Leiden, protein C deficiency, protein S deficiency, anti-thrombin deficiency and prothrombin 20210A mutations.

Thrombophilia affects a large number of people around the world. Factor V Leiden is the most common inherited abnormality in this class. It affects approximately 5% to 7% of the Caucasian population of European descent in the United States.

People who experience episodes of thrombosis, either as an isolated event or as a repeated event, may be affected with a thrombophilic disorder. There are people who have inherited the gene, who have an increased tendency for thrombosis, but may never personally experience a blood clot. Many people can have a known thrombophilic condition and never experience a thrombosis.

The development of a blood clot is called thrombosis. The vascular system includes both the venous system (the veins that deliver blood from the tissues to the heart) and the arterial system (the system that delivers blood from the heart to the tissues). Thrombotic episodes may occur in either system. The symptoms relate to the part of the vascular system in which they occur, the extent of the clot and whether the clot breaks off and travels to another part of the body (e.g., the lungs—pulmonary embolus, the brain—embolic stroke, etc). There are different terms used to further define these thrombotic episodes, such as deep vein thrombosis (DVT) or peripheral vascular disease, when the clots are in the arterial system (usually in the extremities). Although we are now able to determined the underlying cause in some patients and families for this tendency to an increased risk of excessive blood clotting, we are still not able to make this determination in all cases. This means that there is still more to be understood about why some persons and families have thrombophilia.

Recent research shows that these disorders contribute significantly to morbidity and mortality in the United States. Each year, more than 600,000 Americans die from abnormal blood clots.

Even though men and women can have clotting disorders, these conditions pose added difficulties for women because of their relationship to reproductive issues. Women with these disorders can develop serious complications during pregnancy leading to miscarriage. Pregnancy, oral contraceptives and post-menopausal hormone replacement therapy are all triggering events for DVT in women with thrombophilia.

What is thrombophilia?

Thrombophilia is the reverse side of the process of blood clotting when compared to hemophilia. While people with hemophilia have an increased tendency to bleed, people with thrombophilia have an increased tendency to clot. Just as hemophilia is caused by an abnormality of a blood-clotting factor, some forms of thrombophilia are also caused by an abnormality or deficiency of a blood-clotting factor. In some cases these clotting factors may have an abnormality that leads to an increase in their function (such as factor V Leiden).

Thrombophilia is not a new disease, but it has become a more recognized and more discussed due to an increased ability to test for and identify some of the underlying contributing abnormalities

Thrombosis is a very common medical problem. It is estimated that approximately two million people experience a DVT each year in the United States. In addition, nearly half of patients with deep vein clots experience long-term health consequences that adversely affect their quality of life and require millions of dollars of treatment. Thrombosis may manifest itself as the formation or presence of a blood clot in a blood vessel or one of the cavities in the heart. In fact, emboli (clots or plugs brought by the blood from another blood vessel and forced into a smaller vessel so as to obstruct the circulation) from deep vein clots are a leading cause of death in hospitalized patients. Annually, 200,000 to 300,000 patients develop this form of clot for the first time during a hospitalization. Nearly 40% of these patients suffer from a complication known as pulmonary embolism (a clot that travels to the lung and obstructs a significant amount of blood flow to the organ). This complication is fatal in 30% of the cases.

Both children and adults can have thrombophilia. However, it is more commonly diagnosed in adolescents and adults due to normal changes in the hemostatic balance that occur with growth and aging.

Genetic thrombophilia is an inherited abnormality that leads to an increased risk of thrombosis throughout a person's life. The most common inherited thrombophilic disorder is Factor V Leiden, initially described by Dr. Dahlback in 1993. Acquired thrombophilia refers to a group of disorders that an individual is not born with, but may develop throughout his or her life due to another circumstance such as illness. An example of acquired thrombophilia is the development of a lupus anticoagulant or antiphospholipid antibody syndrome.

People with thrombophilia may receive medications that affect the coagulation system, just as people with hemophilia do, but not always in the same manner. Some people with thrombophilia may be perscribed products to treat their thrombophilia either on a long-term or an intermittent basis, depending on the underlying cause of their thrombophilia. Some people with thrombophilia are treated with medications that are classified as blood thinners, which decrease a person's ability to form a clot. Examples of these medications include aspirin, heparin, low molecular weight heparin and coumadin. There are also some specific medications (thrombolytic agents) that are given under certain circumstances to dissolve clots. People with hemophilia , who have central venous access devices that have become clotted, may receive small doses of these medications locally. People with thrombosis may receive these agents in larger doses that are either given at the site of thrombosis or systemically. People with thrombophilia may receive medications only during a time of increased risk of thrombosis or for a prolonged period of time (even for a lifetime), depending on their specific diagnosis and clinical circumstances.

Many healthcare professionals take care of people with thrombophilia. For example, primary healthcare providers (pediatricians, internal medicine physicians, family practitioners, obstetricians and gynecologists, emergency physicians, etc) may all care for patients with this disorder. Subspecialists, such as pulmonologists, vascular surgeons, neurologists and hematologists, may also care for this patient population. Other specialists, such as pathologists and radiologists, may provide services to these patients including diagnostic and interventional services. There is an increasing need to have these patients seen by a team of medical professionals within one facility.

Similar to hemophilia care and prevention services delivered through HTCs, The Centers for Disease Control (CDC) has launched a pilot program to demonstrate the effectiveness of multi-disciplinary comprehensive care to people with clotting disorders.