Severe factor V (FV) deficiency (parahaemophilia) is a rare congenital hemorrhagic disorder characterized by very low or undetectable plasma FV levels and bleeding phenotype ranging from mild to severe. We evaluated whole blood (WB) rotation thromboelastometry (ROTEM) in parahaemophilia patients and the contribution of intraplatelets FV, if any, to clot formation. Standard ROTEM(®) assays were performed in WB from nine parahaemophilia patients and 50 healthy controls. In addition, platelets poor plasma from one parahaemophilia patient (PPP-Pt) or normal subjects (PPP-N) was reconstituted with washed platelets obtained either from one patient with parahaemophilia (Plts-Pt) or normal subjects (Plts-N) and ROTEM assays were performed in platelets rich plasma (PRP) samples. There was a prolongation of the WB clotting time (CT) in all assays in patients as compared with controls. However, maximum clot firmness (MCF) was similar in patients and controls. ROTEM in PPP-Pt showed both a prolongation of CT and a reduction of MCF as compared with PPP-N. The addition of either Plts-Pt or Plts-N to PPP-Pt resulted in similar increase in MCF and a decrease of CT which was more evident for PPP-Pt + Plts-N than PPP-Pt + Plts-Pt. In contrast, the addition of Plts-Pt or Plts-N to PPP-N had superimposable effects on both CT and MCF. In parahaemophilia patients, WB ROTEM(®) presents mainly with prolongation of CT and no relevant effect on MCF. Residual intraplatelets FV in parahaemophilia contributes significantly to thrombin generation as shown in artificially reconstituted PRP models.
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http://dx.doi.org/10.1111/j.1365-2516.2011.02710.x | DOI Listing |
Zhongguo Shi Yan Xue Ye Xue Za Zhi
December 2024
Department of Hematology, The Second Hospital of Shanxi Medical University, Taiyuan 030000, Shanxi Province, China.
Objective: To investigate the clinical phenotype and molecular pathogenic mechanism of a hereditary coagulation factor V deficiency (FⅤD) family.
Methods: A phase I assay was used to measure coagulation factors II, V, VII, VIII, IX, X, Ⅺ, Ⅻ (FⅡ∶C, FⅤ∶C, FⅦ∶C, FⅧ∶C, FⅨ∶C, FⅩ∶C, FⅪ∶C, FⅫ∶C), activated partial thromboplastin time (APTT) and prothrombin time (PT) to determine the clinical phenotype and molecular pathogenesis of F VD. Prothrombin time (PT) were used for phenotypic identification; high-throughput exome sequencing was applied to screen the whole gene variants, and Sanger sequencing was used to verify the suspected variants in gene; MutationTaster, PolyPhen-2 bioinformatics software was used to predict the pathogenicity of the variants, ClustalX software was used to analyze the amino acid conservatism, and PyMol software was used to simulate the model of the mutant protein.
Medicine (Baltimore)
November 2024
Department of Pediatrics, West China Second Hospital, Sichuan University, Chengdu, People's Republic of China.
Rationale: Congenital factor V deficiency is classified as a rare bleeding disorder that is expressed in an autosomal recessive manner and generally occurs in 1 in a million people. This disorder is accompanied by a variety of clinical manifestations, which can easily lead to misdiagnosis. This is the first report to identify the factor V gene variant c.
View Article and Find Full Text PDFBMJ Case Rep
November 2024
UCLA Medical Center Olive View, Sylmar, California, USA.
J Med Case Rep
October 2024
Consultant anaesthetists, Leicester Royal Infirmary, Leicester, UK.
Background: This is an interesting and unexpected thromboembolic event in a hemophiliac patient.
Case Presentation: This is a case of a 33-year-old primigravidarum of Indian Asian origin with Factor V and Factor VIII deficiency who developed a case of pulmonary embolism during the course of her pregnancy after presenting to the emergency department in Leicester, United Kingdom, with hemoptysis, tachycardia, and tachypnea. Patient was subsequently diagnosed with pulmonary embolism after a computed tomography pulmonary angiogram and was treated with therapeutic daltaparin, a low-molecular-weight heparin.
Haemophilia
September 2024
Canadian Blood Services, Medical Affairs and Innovation, Vancouver, Canada.
Introduction: Congenital factor V (FV) deficiency is a rare clotting disorder affecting ∼1 in 1,000,000, with bleeding severity that ranges broadly for poorly understood reasons.
Aim: To help understand the molecular basis of the observed phenotype in FV deficient patients, the genetics and biochemistry causing a patient's FV deficiency were evaluated.
Methods And Results: A 71-year-old female, who had serious life-long bleeding upon provocation and profound menorrhagia that lead to hysterectomy, was found to have 3% of normal plasma FV antigen with normal electrophoretic mobility.
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