1/80. Thermolabile methyltetrahydrofolate reductase associated with unusual venous and arterial thromboses. We report a patient with unusual venous and arterial thromboses in association with the common thermolabile methyltetrahydrofolate (MTHFR) variant. The patient responded directly to folate supplementation. To our knowledge, this is the first report describing hyperhomocysteinemia in association with this type of thrombosis. ( info) |
| A case is presented of a 24 yr old military aircrew applicant who developed a right axillary subclavian deep venous thrombosis following physical exertion. Investigations revealed damage to the right axillary subclavian venous system and limitation to flow. Coagulation studies also showed an elevated plasma homocysteine level. hyperhomocysteinemia has recently been recognized as a risk factor for venous thromboembolic disease. Damage caused by the thrombosis, the hyperhomocysteinemia and environmental factors encountered in flight, may predispose him to recurrent episodes of thrombosis. This complex case involves aspects of hematology and the nature of coagulation which are only just being elucidated and as yet are poorly understood, and highlights some serious aeromedical implications for pilots afflicted with these conditions. ( info) |
3/80. hyperhomocysteinemia, aortic thrombus, and peripheral arterial emboli--a case report. A young Native American woman presented with ischemia of the left lower limb resulting from embolic occlusion of the left common iliac artery and left femoral artery. The source of her emboli was aortic thrombus. The only underlying abnormality responsible for her hypercoagulability appeared to be hyperhomocysteinemia. ( info) |
4/80. Inherited protein c deficiency, protein s deficiency and hyperhomocysteinaemia in a patient with hereditary spherocytosis. We report a family with hereditary spherocytosis in whom there is, in addition, a cluster of genetic predispositions to thrombosis. Although inherited prothrombotic abnormalities are prevalent in the general population, the likelihood of this combination of abnormalities being found in a single family is extremely low. The management of such high risk individuals is discussed. ( info) |
| A case is presented in which superior vena cava (SVC) syndrome was caused by a stenosis of the SVC due to thrombosis. hyperhomocysteinemia was diagnosed as a possible underlying mechanism. The role of hyperhomocysteinemia as a risk factor for the development of recurrent venous thrombosis, its diagnosis, and treatment are discussed. ( info) |
| Severe hyperhomocysteinemia due to cystathionine beta-synthase (CBS) deficiency is a strong risk factor for premature cardiovascular disease. Among untreated patients, approximately 50% have suffered a thromboembolic event by 30 years of age. We report on 3 sisters with severe hyperhomocysteinemia due to homozygosity for the CBS 833T-->C mutation. These patients, who displayed no other known thrombophilic predisposition, had suffered single or multiple venous thrombosis before CBS deficiency was diagnosed relatively late in life. In this family, homozygosity for the 833T-->C mutation was associated with a mild phenotype with respect to other sequelae of CBS deficiency. Consequently, our results indicate that most cases with this genotype may remain undiagnosed. Investigated family members heterozygous for the 833T-->C mutation displayed normal total homocysteine in plasma (tHcy) levels, even when they were homozygous for the methylenetetrahydrofolate reductase 677C-->T polymorphism. The prevalence of homozygosity for the 833T-->C mutation has previously been estimated at no less than 1:20 500 in our population. Because a reduction of the severely elevated levels of tHcy in CBS deficiency reduces cardiovascular risk and because homozygosity for the 833T-->C mutation is more prevalent than previously thought, our results emphasize the importance of measuring tHcy routinely in thrombophilia screening. ( info) |
7/80. Low molecular weight heparin in the successful treatment of a spontaneous aortic thrombosis in a neonate. A successfully treated case of a spontaneous aortic thrombosis in a neonate is described as an illustration of the advantages of using low molecular weight heparin (LMWH) over unfractionated heparin (UFH) for anticoagulation therapy. A 5-day-old neonate presented with an abdominal aortic thrombosis detected by echocardiography. Intravenous UFH was commenced following thrombectomy. Poor venous access made monitoring the anticoagulation therapy problematic. Subcutaneous LMWH was substituted for UFH. It requires substantially less monitoring and no intravenous access, has fewer side effects, and allows for much earlier discharge from the hospital. Extensive investigation for a hypercoagulable state revealed no definite cause for the thrombus. The findings of homozygosity for a methylene tetrahydrofolate reductase (MTHFR) mutation and a mildly elevated homocysteine level are interesting but unlikely to account for the thrombotic event in this case. Anticoagulation with LMWH proved effective and more convenient than using UFH. ( info) |
| Behcet's disease (BD) is known for its tendency for thromboembolism, which is thought to be due to vascular injury. The important role of inherited thrombophilias is now becoming increasingly clear. However, conflicting data exist in terms of the contribution of these factors to the thrombotic risk in BD. In this case report, we describe a patient with BD who presented with severe cor pulmonale due to recurrent chronic venous thromboembolism and pulmonary artery thrombosis. The biochemical evaluation revealed that the patient was homozygotic for the factor v Leiden (R506Q) mutation and had increased levels of homocysteine. His condition deteriorated despite adequate anticoagulation treatment, and he died suddenly after 7 months of follow-up. We assume that the presence of thrombophilic risk factors augments and synergizes with the hypercoagulable state already existing in BD, leading to fatal thrombosis in this patient. ( info) |
9/80. Giant coronary aneurysms with multiple vascular aneurysms: a rare manifestation of hyperhomocysteinemia. hyperhomocysteinemia is associated with accelerated atherosclerosis, which leads to an increased incidence of premature vascular disease. Although multiple vascular aneurysms have been linked to hyperhomocysteinemia, coronary artery aneurysms have not. We report a case of giant coronary artery aneurysm associated with multiple peripheral vascular aneurysms in a patient with hyperhomocysteinemia. ( info) |
10/80. Acute renal vein thrombosis, oral contraceptive use, and hyperhomocysteinemia. Oral contraceptive use and hyperhomocysteinemia are considered to be relatively weak risk factors for venous thromboembolism. We report a case of acute renal vein thrombosis, a rare and aggressive form of thromboembolism, that occurred in a 21-year-old woman taking oral contraceptives, who was subsequently found to have marked hyperhomocysteinemia. This case suggests that the oral contraceptive and hyperhomocysteinemia may interact in a synergistic manner in the pathogenesis of thrombosis. In oral contraceptive users who develop venous thrombosis in the absence of other risk factors, clinicians should consider investigations for an underlying prothrombotic biochemical disorder. ( info) |