Genetic testing for the angiotensin-converting enzyme (ACE) gene genotype is performed to assess the risk of thrombosis in asymptomatic patients with a strong family history or in patients who have already had a thromboembolic event.
The ACE gene on chromosome 17 codes for the angiotensin-converting enzyme. This enzyme is part of the renin-angiotensin system, which regulates blood pressure and the body's balance of fluids and electrolytes. With the help of an angiotensin-converting enzyme, the protein angiotensin II is formed by converting a protein called angiotensin I. Angiotensin II causes blood vessels to constrict, which leads to increased blood pressure. This protein also stimulates the production of the hormone aldosterone, which triggers the absorption of salt and water by the kidneys. The Del/Del genotype of the ACE gene is associated with high levels of angiotensin in the blood, which can cause hypertension, diabetic nephropathy, and thromboembolic events. The Del/Del genotype has also been associated with an increased risk of hypertension during pregnancy, resulting in mild preeclampsia. The simultaneous presence of the MTHFR 1298C allele appears to increase this risk. The Ins/Ins genotype is associated with low levels of angiotensin-converting enzyme, while the Ins/Del genotype is associated with intermediate enzyme levels.
Thrombophilia is an acquired or congenital disorder associated with thrombosis. The clinical presentation of an underlying thrombophilia mainly includes venous thromboembolism manifesting as deep vein thrombosis, pulmonary embolism, or superficial vein thrombosis. Other manifestations that have been associated with thrombophilia include recurrent miscarriages and pregnancy complications such as severe preeclampsia, placental abruption, and intrauterine fetal death. Demographic and environmental characteristics that contribute to the risk of venous thromboembolism in people with a predisposition to thrombophilia include older age, gender (more common in men), obesity, surgeries, injuries, hospitalization for other diseases, malignant neoplasms, prolonged immobility (such as long plane trips), the use of certain medications (such as contraceptives, estrogens, tamoxifen and raloxifene, and certain medications used to treat infertility).
