1/9. Interatrial septal aneurysm and genetic prothrombotic disorders: possible interaction in the pathogenesis of pediatric stroke. stroke in children is a rare condition and has a multifactorial etiology. The association between ischemic stroke in young adults and some minor cardiac abnormalities such as atrial septal aneurysm with or without interatrial shunting has recently been reported: however, the pathogenetic mechanism still remains unclear. Genetic and acquired prothrombotic disorders are also risk factors for cerebral ischemic events in children. We report a case of ischemic stroke in a 10-year-old female child who was heterozygous for the prothrombin G20210A variant and who presented with an atrial septal aneurysm associated with an interatrial shunt. We hypothesize that these risk factors play a synergic role but their relative importance and whether alone they can determine cerebral embolism remain to be determined. ( info) |
| Hypercoagulability is one of the causes of portal vein and superior mesentery vein thrombosis. We report a case of bacteroides fragilis bacteremia associated with portal vein and superior mesentery vein thrombosis secondary to antithrombin iii and protein c deficiency. The patient presented with high fever for more than 3 weeks. Abdominal sonography revealed a liver cyst of 1.7 cm in diameter over segment 4 and a renal stone of 0.7 cm in size over the lower portion of the right kidney but no evidence of hydronephrosis. Elevation of liver enzymes was also noted. Intermittent fever was noted despite treatment with ceftriaxone and doxycycline. On Day 15 of hospitalization, blood culture revealed B. fragilis, which prompted further investigation of the source of intraabdominal and pelvic infection. Abdominal computed tomography revealed portal vein and superior mesentery vein thrombosis. Endoscopic studies of the gastrointestinal tract showed no tumor or diverticulum. Study of coagulation factors disclosed deficiency of antithrombin iii and protein C. Clinicians should remain aware of the need to promptly search for a portal or mesentery vein thrombosis in cases of Bacteroides bacteremia of unknown origin. ( info) |
| We present the case of a newborn male with D-transposition of the great arteries, ventricular septal defect, and subpulmonary stenosis who experienced two episodes of systemic-to-pulmonary artery shunt thrombosis. Hematologic evaluation revealed heterozygous factor v Leiden mutation. This report emphasizes the importance of evaluation for inherited coagulation disorders in pediatric patients with unexpected thrombotic complications. ( info) |
4/9. Unsuspected mesenteric vein thrombosis in a patient with a hereditary bleeding disorder. We report on a female patient with hereditary hemorrhagic teleangiectasia complicated by subacute thrombosis of the superior mesenteric vein. Despite gastrointestinal bleeding, anticoagulation therapy with heparin had to be performed to prevent bowel infarction. In this case, local vascular lesions with altered blood flow in combination with hyperfibrinogenemia might have caused superior mesenteric vein thrombosis. ( info) |
5/9. A novel missense mutation in ABCA1 results in altered protein trafficking and reduced phosphatidylserine translocation in a patient with Scott syndrome. Scott syndrome (SS) is a bleeding disorder characterized by a failure to expose phosphatidylserine (PS) to the outer leaflet of the platelet plasma membrane. Because the adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) is implicated in the exofacial translocation of PS, we assessed its role in the pathophysiology of a patient with SS. Substantially reduced levels of ABCA1 mRNA were found in the patient's leukocytes, compared with controls. The SS patient was heterozygous for a novel missense mutation c.6064G>A (ABCA1 R1925Q), absent from unaffected family members and controls. Both mutant and wild-type alleles were reduced in mRNA expression, and no causative mutation for this phenomenon was identified in the ABCA1 gene or its proximal promoter, suggesting a putative second mutation in a trans-acting regulatory gene may also be involved in the disorder in this patient. in vitro expression studies showed impaired trafficking of ABCA1 R1925Q to the plasma membrane. Overexpression of wild-type ABCA1 in SS lymphocytes complemented the Ca2 -dependent PS exposure at the cell surface. These data identify a mutation in ABCA1 that contributes to the defective PS translocation phenotype in our patient with SS. ( info) |
6/9. Identification of a novel amino acid deletion mutation and a very rare single nucleotide variant in a Japanese family with type I antithrombin deficiency. We studied a Japanese family with type I antithrombin (AT) deficiency and identified a novel in-frame deletion mutation (-ATG at nucleotide position of 2771-2773) in the AT gene, which predicted loss of a methionine (Met) at amino acid number of 103. In addition, we found a single base replacement of G to A at nucleotide position of 67 (4 base upstream to the initial codon) in the mutant allele. Since the G67A substitution in the AT gene was very rare, this family was the second case, in which the nucleotide change was transmitted. To elucidate the mechanism of AT deficiency, we transiently expressed wild type and the mutant AT (DeltaM103) in HuH-7 human hepatoma cells and performed pulse-chase studies. The experiments revealed that the mutant AT (DeltaM103) hardly secreted into the medium and underwent partial intracellular degradation. In addition, we performed luciferase reporter assay to examine the effect of G67A substitution on the AT gene expression, and found that the substitution did not reduce the luciferase activity. These results suggested that secretion defect and intracellular degradation of the variant molecule with the deletion of Met 103 were responsible for AT deficiency in this family. ( info) |
7/9. Ischaemic colitis mimicking inflammatory bowel disease in a young adult receiving oral anticoagulation. Ischaemic colitis (IC) is the most frequent form of gastrointestinal ischaemia. Discrepancy between non-specific symptoms and objective findings is a hallmark of IC. Thus delay of diagnosis is common due to its often subtle and unpredictable presentation. In particular, the clinical symptoms and signs of IC can overlap with those of inflammatory bowel disease. We present a case of a young man with known factor-V-Leiden mutation in whom IC developed during effective therapy with oral anticoagulants, presenting with symptoms and endoscopic findings suggestive of inflammatory bowel disease. ( info) |
8/9. budd-chiari syndrome as the first manifestation of polycythemia vera in young women with inherited thrombophilic state: an aggressive form of myeloproliferative disorder requiring multidisciplinary management. The budd-chiari syndrome (BCS), characterized by the obstruction and occlusion of the suprahepatic veins, is a rare but typical complication occurring in patients with polycythemia vera (PV). We describe three young women who developed BCS as first manifestation of PV, in association with an inherited thrombophilic state and in the absence of concomitant use of oral contraceptives. Our report illustrates the existence of an aggressive form of myeloproliferative disorder, which requires prompt recognition and immediate therapeutic intervention including cytostatic drugs and anticoagulant treatment. Furthermore, we suggest the need of routine screening for thrombophilic state in young women affected by PV. ( info) |
9/9. Compound heterozygosity of novel missense mutations in the gamma-glutamyl-carboxylase gene causes hereditary combined vitamin k-dependent coagulation factor deficiency. Hereditary combined vitamin k-dependent (VKD) coagulation factor deficiency is an autosomal recessive bleeding disorder associated with defects in either the gamma-carboxylase, which carboxylates VKD proteins to render them active, or the vitamin k epoxide reductase (VKORC1), which supplies the reduced vitamin k cofactor required for carboxylation. Such deficiencies are rare, and we report the fourth case resulting from mutations in the carboxylase gene, identified in a Tunisian girl who exhibited impaired function in hemostatic VKD factors that was not restored by vitamin k administration. sequence analysis of the proposita did not identify any mutations in the VKORC1 gene but, remarkably, revealed 3 heterozygous mutations in the carboxylase gene that caused the substitutions Asp31Asn, Trp157Arg, and Thr591Lys. None of these mutations have previously been reported. family analysis showed that Asp31Asn and Thr591Lys were coallelic and maternally transmitted while Trp157Arg was transmitted by the father, and a genomic screen of 100 healthy individuals ruled out frequent polymorphisms. Mutational analysis indicated wild-type activity for the Asp31Asn carboxylase. In contrast, the respective Trp157Arg and Thr591Lys activities were 8% and 0% that of wild-type carboxylase, and their compound heterozygosity can therefore account for functional VKD factor deficiency. The implications for carboxylase mechanism are discussed. ( info) |