A NOVEL THROMBOMODULIN GENE MUTATION IN A PATIENT SUFFERING FROM SAGITTAL SINUS THROMBOSIS

Thrombomodulin is an endothelial cell membrane glycoprotein that promo tes protein C activation. It has been clearly demonstrated that the an ticoagulant functions of the protein C system are important in the pre vention of thromboembolic disease. Patients with protein C or protein S deficiency and/or resistance to activated protein C (APC resistance) are at higher risk for developing thromboembolic disease. The first m utation in the thrombomodulin gene was discovered in an American patie nt suffering from pulmonary embolism at the age of 45 (Ohlin and Marla r 1995). Here we report a case of sagittal sinus thrombosis in a 42-ye ar-old Swedish woman. She was found to carry a heterozygous point muta tion changing G(127) to A, predicting an Ala(25) to a Thr change in th e mature thrombomodulin protein. This mutation was also found in her 1 6-year-old daughter, who so far has not suffered from any thrombotic e vents. The patient had no other detectable prothrombotic genetic defec ts associated with the coagulation system. This case supports the hypo thesis of an association between mutations in the thrombomodulin gene and venous thrombosis.