Hereditary Antithrombin Deficiency

Hereditary antithrombin deficiency, also known as antithrombin III deficiency or AT III deficiency, is a disorder in which individuals are at increased risk for developing blood clots. The type of blood clots seen in individuals with this condition are typically clots that form in the deep veins of the leg (deep vein thrombosis or DVT) and clots that lodge in the lungs (pulmonary embolism or PE). Approximately 50% of individuals with hereditary antithrombin deficiency will develop one or more clots in their lifetime, usually after adolescence. Factors that may increase the likelihood of clotting include pregnancy, the use of oral contraceptives, surgery, increasing age, and a lack of movement. Hereditary antithrombin deficiency is caused by mutations in the SERPINC1 gene and is typically inherited in an autosomal dominant manner.