Heterozygous FGA p.Asp473Ter (fibrinogen Nieuwegein) presenting as antepartum cerebral thrombosis.

INTRODUCTION: The propositus - a two-week-old boy - was transferred to our university hospital for investigation of increased head circumference and full fontanel. On ultrasound, thrombosis of the right internal cerebral vein and intraventricular haemorrhage was diagnosed, confirmed by MRI. Family history revealed a bleeding history in the mother. A haemostatic work-up in both mother and child was performed in order to rule out congenital coagulopathy. AIM: We document a clinical case of congenital dysfibrinogenemia, caused by heterozygosity for the mutation FGA p.Asp473Ter, previously reported as fibrinogen Nieuwegein in homozygosity in an asymptomatic patient. METHODS: Fibrinogen activity in plasma was determined by functional Clauss assay, and immunological fibrinogen concentration by nephelometry. In vitro fibrin clot investigations and genetic analysis of the fibrinogen gene were performed. Complete haemostatic work-up was done by conventional methods. RESULTS AND DISCUSSION: After full laboratory work-up, dysfibrinogenemia was diagnosed, based on fibrinogen activity:antigen ratio, thrombin time, and reptilase time. Molecular analysis showed a frameshift mutation in exon 5 of FGA: c.1415_1416 insC, leading to a termination codon immediately after the insertion (CCT GAT>CCC TGA) and resulting in a truncated αC-domain. This mutation has been reported earlier as fibrinogen Nieuwegein. Further in vitro investigations revealed an abnormally tight clot structure, prolonged clot lysis time and affected polymerization, suggesting a thrombotic phenotype. Cerebral imaging revealed thrombosis, most likely developed in the antenatal period, leading to extensive intraventricular haemorrhage and posthaemorrhagic ventricular dilatation. CONCLUSION: We highlight the combined thrombotic and haemorrhagic phenotype linked to heterozygous fibrinogen Nieuwegein, in contrast to the previously reported asymptomatic homozygous case.

Congenital dysfibrinogenemia in a Japanese family with fibrinogen Naples (BßAla68Thr) manifesting as superior sagittal sinus thrombosis.

: Congenital dysfibrinogenemia refers to the presence of a dysfunctional fibrinogen molecule, typically because of mutations in the fibrinogen gene. About 20% of fibrinogen gene mutations are responsible for thrombosis. Here, we described the case of a 17-year-old Japanese boy, who had a sudden stroke because of superior sagittal sinus thrombosis associated with dysfibrinogenemia. Genetic testing confirmed the presence of homozygous fibrinogen Naples (BßAla68Thr) mutation, which was previously reported as a causative mutation for thrombotic dysfibrinogenemia only in an Italian family. In this Japanese family, the patient's 12-year-old asymptomatic sister was also homozygous for this mutation. She, like her brother, was started on warfarin therapy. This report highlights the occurrence of fibrinogen Naples that has caused severe thrombotic complications in a young member of a Japanese family.

Hematopoietic stem cell transplantation for Hodgkin's disease in a patient with dysfibrinogenemia and thrombosis.

INTRODUCTION: Dysfibrinogenemia is a disorder of fibrinogen structure and is associated with a functional abnormality. Since fibrinogen is a key component of both the procoagulant and fibrinolytic pathways, defects in fibrinogen function can be associated with increased risk for both hemorrhage and thrombosis. Management of patients with dysfibrinogenemia and a thrombotic tendency usually involves long-term anticoagulation. CASE: A 36-year-old male with relapsed nodular sclerosing Hodgkin's was found to have a prolonged prothrombin time, low fibrinogen activity and a normal fibrinogen antigen during evaluation for a hematopoietic peripheral blood stem cell transplant. His past medical history was significant for an acute myocardial infarction and two episodes of acute pancreatitis. His father had dysfibrinogenemia complicated by multiple thrombotic episodes. A trans-esophageal echocardiogram revealed two thrombi, one each in the superior vena cava and the descending aorta. He was treated with enoxaparin and received peripheral blood stem cell transplantation. An effort was made to maintain his fibrinogen activity levels at 200 mg/dL using cryoprecipitate. A month following the transplant he developed a new thrombus in the right internal jugular vein, while on enoxaparin and he was started on argatroban and cryoprecipitate followed by fondaparinux. A repeat echocardiogram six weeks later demonstrated that the burden of thrombus both in the right atrium and descending aorta was significantly lower. DISCUSSION: This is the first case report of a patient with dysfibrinogenemia undergoing peripheral blood stem cell transplantation. Conventional anticoagulant therapy and cryoprecipitate seem to be a reasonable management strategy to prevent thrombosis in a patient with dysfibrinogenemia and a thrombophilic tendency. Secondly, fondaparinux can be used in cases of failure of therapy with low molecular weight heparins and may actually be superior to low molecular weight heparins, especially in patients with dysfibrinogenemia.

Fibrinogen Alès: a homozygous case of dysfibrinogenemia (gamma-Asp(330)-->Val) characterized by a defective fibrin polymerization site "a".

Congenital homozygous dysfibrinogenemia was diagnosed in a man with a history of 2 thrombotic strokes before age 30. His hemostatic profile was characterized by a dramatically prolonged plasma thrombin clotting time, and no clotting was observed with reptilase. Complete clotting of the abnormal fibrinogen occurred after a prolonged incubation of plasma with thrombin. The release of fibrinopeptides A and B by thrombin and of fibrinopeptide A by reptilase were both normal. Thrombin-induced fibrin polymerization was impaired, and no polymerization occurred with reptilase. The polymerization defect was characterized by a defective site "a," resulting in an absence of interaction between sites A and a, indicated by the lack of fragment D(1) (or fibrinogen) binding to normal fibrin monomers depleted in fibrinopeptide A only (Des-AA fm). By SDS-PAGE, the defect was detected on the gamma-chain and in its fragment D(1). The molecular defect determined by analysis of genomic DNA showed a single base change (A-->T) in exon VIII of the gamma-chain. The resulting change in the amino acid structure is gamma 330 aspartic acid (GAT) --> valine (GTT). It is concluded that the residue gamma-Asp(330) is essential for the normal functioning of the polymerization site a on the fibrinogen gamma-chain.

Cryofibrinogenemia in a patient with B-cell lymphoma.

Cryofibrinogenemia is an uncommon cause of intravascular coagulation necrosis of the skin and occurs as a result of vascular occlusion from cryoproteins, which reversibly precipitate in cold temperatures. The disease is associated with various conditions, most commonly neoplastic and thromboembolic diseases, and produces cutaneous manifestations such as purpura, ecchymoses, gangrene, and ulcerations. Diagnosis is based on clinical cutaneous manifestations, histopathology, and the laboratory detection of cryofibrinogen precipitation. Treatment is based upon resolution of the underlying disease process or condition, although some interventions have been reported to have therapeutic efficacy. We discuss the presentation, diagnosis, and treatment of a case of cryofibrinogenemia in a patient with underlying B-cell lymphoma.

Cryofibrinogenemia and skin necrosis in a patient with diffuse large cell lymphoma after high-dose chemotherapy and autologous stem cell transplantation.

A 34-year-old woman with diffuse mediastinal B cell large cell lymphoma presented 60 days after high-dose chemotherapy and autologous stem cell transplantation, and post-transplant immunotherapy with interleukin-2, with skin necrosis in the ears and extremities. Extensive work-up revealed the presence of cryofibrinogenemia and associated thrombotic vasculopathy. The patient was successfully treated with corticosteroids and therapeutic plasma exchange. However, she had recurrence of large cell lymphoma a few weeks later and died of progressive disease. Cryfibrinogenemia and skin necrosis may have occurred secondary to the imminent relapse, or as a rare complication of high-dose chemotherapy or treatment with interleukin-2.