Heredity is often to blame for blood clotting disorders. Some genetic disorders of the blood cause deficiencies in protein factors that control blood coagulation and increase the risk of developing a blood clot. Excessive coagulation due by heredity is called inherited thrombophilia.Heredity, Thrombophilia and Blood Clot Risk Factors. Inherited thrombophilia affects up to eight percent of the U.S. population. Many people with genetic coagulation disorders lead normal lives and never experience a blood clot. However, when hereditary risk factors are coupled with other blood clot risks, the chance of developing a clot or deep vein thrombosis increases. A deep vein thrombosis is a dangerous blood clot that forms in the larger, deep blood vessels. Pieces of this type of clot can break off and travel to vital organs where they may stop blood flow.
Factors that can increase the risk of blood clots, especially when combined with genetic disorders include:
having more than one type of inherited thrombophilia
oral contraceptive use
Heredity and Causes of Thrombophilia. Genetic mutations can affect a number of proteins that affect coagulation. Deficiencies in protein C, protein S, factor V Leiden, and antithrombin III all increase the chances of blood clot formation. Genetic defects in prothrombin 20210a and methylene tetrahydrofolate reductase result in low levels of the proteins prothrombin and homocysteine, which negatively affect hemostasis.Factor V Leiden. Factor V Leiden is the most common form of thrombo-philia in the US, affecting five percent of the Caucasian population and just over one percent of Black Americans. The factor V Leiden mutation prevents activated protein C (APC) from breaking down protein factor V. Factor V is a protein involved in generating clots. Hence, as excess amounts of factor V build up in the blood, the risk of developing a blood clot is increased. Factor V Leiden is also known as activated protein C resistance, or APC resistance. The genetic disorder is detected by a simple blood test.
Heredity also plays a role in determining the likelihood of factor V Leiden causing dangerous blood clots. The genetic disorder can be passed-on by either parent. One factor V Leiden gene increases the chances of deep vein thrombosis by three to eight times the normal risk. People who inherit factor V Leiden genes from both parents are 30 to 140 times more likely to develop blood clotting complications, including venous thrombosis, ulmonary embolism, and strokes. Women with this form of hrombophilia are more likely to experience toxemia while pregnant and are at greater risk of stillbirths or repeated miscarriages.