is implicated in central nervous system, orofacial and maxillofacial anomalies.

Background: Previous studies in mouse, and zebrafish embryos show strong expression in progenitor cells of neuronal and neural crest tissues suggesting its involvement in neural crest specification. However, the role of human transcription factor activator protein 2 ( in human embryonic central nervous system (CNS), orofacial and maxillofacial development is unknown.

Methods: Through a collaborative work, exome survey was performed in families with congenital CNS, orofacial and maxillofacial anomalies.

Modulation of Haemostatic Balance in Combined von Willebrand Disease and Antithrombin Deficiency: A Comprehensive Family Study.

Introduction: Maintaining the balance between procoagulant and anticoagulant factors is essential for effective haemostasis. Emerging evidence suggests a modulation of bleeding tendency by factors in the anticoagulant and fibrinolytic systems.

Aim: This study investigates the clinical and laboratory characteristics of a family with combined von Willebrand disease (VWD) and antithrombin (AT) deficiency.

Comprehensive evaluation of anti-emicizumab antibodies in acquired hemophilia A: a detailed case study and methodological evaluation.

Background: Acquired hemophilia A (AHA) is a rare and severe bleeding disorder characterized by autoantibodies inhibiting coagulation factor (F)VIII. Current treatment of AHA involves bypassing agents or FVIII replacement therapy, yet their efficacy is limited in cases of high inhibitor titers. Emicizumab, a humanized bispecific monoclonal antibody, has shown promising hemostatic effectiveness in persons with congenital hemophilia A (HA) and AHA, but a minority of patients developed anti-drug antibodies (ADAs), compromising its efficacy.

Unravelling the spectrum of von Willebrand factor variants in quantitative von Willebrand disease: results from a German cohort study.

Background: Von Willebrand disease (VWD), the most prevalent hereditary bleeding disorder, results from deficiency of von Willebrand factor (VWF).

Objectives: This large cohort study aims to offer a comprehensive exploration of mutation spectra and laboratory features in quantitative VWF deficiencies, shedding light on genetic underpinnings and genotype-phenotype associations.

Methods: Our cohort consisted of 221 Caucasian index patients with quantitative VWD, along with 47 individuals whose plasma VWF levels fell within the lower normal boundaries (50-70 IU/dL).

In-depth structure-function profiling of the complex formation between clotting factor VIII and heme.

Background And Aims: Blood disorders, such as sickle cell disease, and other clinical conditions are often accompanied by intravascular hemolytic events along with the development of severe coagulopathies. Hemolysis, in turn, leads to the accumulation of Fe(II/III)-protoporphyrin IX (heme) in the intravascular compartment, which can trigger a variety of proinflammatory and prothrombotic reactions. As such, heme binding to the blood coagulation proteins factor VIII (FVIII), fibrinogen, and activated protein C with functional consequences has been demonstrated earlier.

Comprehensive domain-specific analysis and immunoglobulin G profiling of anti-factor VIII antibodies using a bead-based multiplex immunoassay.

Background: Antibodies against factor (F)VIII are a major complication in the treatment of patients with severe hemophilia A. The Nijmegen-Bethesda assay (NBA) is the gold standard for detection of neutralizing antibodies (inhibitors), whereas both inhibitors and nonneutralizing antibodies can be detected by immunoassays such as enzyme-linked immunosorbent assay (ELISA) and multiplex bead-based assays.

Objectives: Evaluation of an in-house Luminex bead-based assay (LumiTope) compared with a commercially available ELISA and NBA.

Heterozygosity in factor XIII genes and the manifestation of mild inherited factor XIII deficiency.

Background: The characterization of inherited mild factor XIII deficiency is more imprecise than its rare, inherited severe forms. It is known that heterozygosity at FXIII genetic loci results in mild FXIII deficiency, characterized by circulating FXIII activity levels ranging from 20% to 60%. There exists a gap in information on 1) how genetic heterozygosity renders clinical bleeding manifestations among these individuals and 2) the reversal of unexplained bleeding upon FXIII administration in mild FXIII-deficient individuals.

Fibrinogen Bonn (p. Arg510Cys) in the Aα-Chain Is Associated with High Risk of Venous Thrombosis.

Introduction:  Inherited dysfibrinogenemia is a qualitative defect of fibrinogen caused by various mutations among three fibrinogen genes. Dysfibrinogenemia can be associated with an increased risk of thrombosis, bleeding, or both. Here, we report a 36-year-old female with dysfibrinogenemia who experienced two successful pregnancies under thromboprophylaxis after cerebral venous sinus thrombosis (CVST).

Antidrug antibodies against the polyethylene glycol moiety inhibit the procoagulant activity of therapeutic polyethylene glycolated factor VIII.

Background: The standard therapy for patients with hemophilia A (HA) is the replacement with factor VIII (FVIII) therapeutics. To overcome the limitation of short half-life of wild-type FVIII protein, polyethylene glycol (PEG) can be coupled to therapeutic FVIII to improve pharmacokinetics.

Objectives: We aimed to characterize antibodies developed against a FVIII therapeutic PEGylated with a 40-kDa PEG (40PEG-BDD) in 2 patients with mild HA.

Insights into the Molecular Genetic of Hemophilia A and Hemophilia B: The Relevance of Genetic Testing in Routine Clinical Practice.

Hemophilia A and hemophilia B are rare congenital, recessive X-linked disorders caused by lack or deficiency of clotting factor VIII (FVIII) or IX (FIX), respectively. The severity of the disease depends on the reduction of coagulation FVIII or FIX activity levels, which is determined by the type of the pathogenic variants in the genes encoding the two factors ( and , respectively). Molecular genetic analysis is widely applied in inherited bleeding disorders.

Experiences in Routine Genetic Analysis of Hereditary Hemorrhagic, Thrombotic, and Platelet Disorders.

Hemostasis is a complex and tightly regulated system that attempts to maintain a homeostatic balance to permit normal blood flow, without bleeding or thrombosis. Hemostasis reflects the subtle balance between procoagulant and anticoagulant factors in the pathways of primary hemostasis, secondary hemostasis, and fibrinolysis. The major components in this interplay include the vascular endothelium, platelets, coagulation factors, and fibrinolytic factors.

Functional Characterization of Antithrombin Mutations by Monitoring of Thrombin Inhibition Kinetics.

Inactivation of thrombin by the endogenous inhibitor antithrombin (AT) is a central mechanism in the regulation of hemostasis. This makes hereditary AT deficiency, which is caused by SERPINC1 gene mutations, a major thrombophilic risk factor. Aim of this study was to assess to what extent AT mutations impair thrombin inhibition kinetics.

Familial Multiple Coagulation Factor Deficiencies (FMCFDs) in a Large Cohort of Patients-A Single-Center Experience in Genetic Diagnosis.

Background: Familial multiple coagulation factor deficiencies (FMCFDs) are a group of inherited hemostatic disorders with the simultaneous reduction of plasma activity of at least two coagulation factors. As consequence, the type and severity of symptoms and the management of bleeding/thrombotic episodes vary among patients. The aim of this study was to identify the underlying genetic defect in patients with FMCFDs.

Further Evidence That MicroRNAs Can Play a Role in Hemophilia A Disease Manifestation: Gene Downregulation by miR-19b-3p and miR-186-5p.

Hemophilia A (HA) is a gene mutational disorder resulting in deficiency or dysfunctional FVIII protein. However, surprisingly, in few cases, HA is manifested even without mutations in . To understand this anomaly, we recently sequenced microRNAs (miRNAs) of two patients with mild and moderate HA with no gene mutations and selected two highly expressing miRNAs, miR-374b-5p and miR-30c-5p, from the pool to explain the FVIII deficiency that could be mediated by miRNA-based /FVIII suppression.

Selective Modulation of the Protease Activated Protein C Using Exosite Inhibiting Aptamers.

Activated protein C (APC) is a serine protease with anticoagulant and cytoprotective activities. Nonanticoagulant APC mutants show beneficial effects as cytoprotective agents. To study, if such biased APC signaling can be achieved by APC-binding ligands, the aptamer technology has been used.

Clinical manifestation of hemophilia A in the absence of mutations in the F8 gene that encodes FVIII: role of microRNAs.

Background: Hemophilia A (HA) is associated with mutations in the F8 gene that expresses factor VIII (FVIII). Unexpectedly, HA also manifests in a small subset of individuals with no mutations (exonic or intronic) in their F8 gene. MicroRNAs (miRNAs) cause translational interference, affecting protein quality and stoichiometry.

Risk stratification integrating genetic data for factor VIII inhibitor development in patients with severe hemophilia A.

Replacement therapy in severe hemophilia A leads to factor VIII (FVIII) inhibitors in 30% of patients. Factor VIII gene (F8) mutation type, a family history of inhibitors, ethnicity and intensity of treatment are established risk factors, and were included in two published prediction tools based on regression models. Recently investigated immune regulatory genes could also play a part in immunogenicity.

F8 Inversions at Xq28 Causing Hemophilia A Are Associated With Specific Methylation Changes: Implication for Molecular Epigenetic Diagnosis.

Diverse DNA structural variations (SVs) in human cancers and several other diseases are well documented. For genomic inversions in particular, the disease causing mechanism may not be clear, especially if the inversion border does not cross a coding sequence. Understanding about the molecular processes of these inverted genomic sequences, in a mainly epigenetic context, may provide additional information regarding sequence-specific regulation of gene expression in human diseases.

In silico and in vitro evaluation of the impact of mutations in non-severe haemophilia A patients on assay discrepancies.

Haemophilia A (HA) is caused by a lack or reduced amount of factor VIII protein (FVIII). About one-third of patients with non-severe HA carrying specific missense mutations show discrepant results between FVIII activity (FVIII:C), measured by one-stage or chromogenic two-stage assays. The aim of this study was to elucidate the mechanism underlying the assay discrepancy in vitro and in silico.

Variants in FIX propeptide associated with vitamin K antagonist hypersensitivity: functional analysis and additional data confirming the common founder mutations.

One of the most common and unwanted side effects during oral anticoagulant therapy (OAT) is bleeding complications. In rare cases, vitamin K antagonist (VKA)-related bleeding events are associated with mutations affecting the F9 propeptide at amino acid position 37 due to a substitution of alanine to either valine or threonine. Based on our actual cohort of 18 patients, we update the knowledge on this rare phenotype and its origin.

An in silico and in vitro approach to elucidate the impact of residues flanking the cleavage scissile bonds of FVIII.

Coagulation Factor VIII is activated by an ordered limited thrombin proteolysis with different catalytic efficiency at three P1 Arginine residues: Arg759> Arg1708>Arg391, indicating the flanking residues of the latter to be less optimal. This study aimed to investigate, in silico and in vitro, the impact of possessing hypothetically optimized residues at these three catalytic cleavage sites. The structural impact of the residues flanking Arginine cleavage sites was studied by in silico analysis through comparing the cleavage cleft of the native site with a hypothetically optimized sequence at each site.

Combined coagulation factor VIII and factor IX deficiency (CDF8F9) in a patient from Lithuania.

Unlabelled: Haemophilia A (FVIII deficiency) and haemophilia B (FIX deficiency) are X-linked inherited bleeding disorders. It is a very rare event to identify both haemophilias in the same patient. So far, only two families with such combination are reported in the literature worldwide supported by genetic background.

Evidence of pathogenicity of a mutation in 3' untranslated region causing mild haemophilia A.

Introduction: Despite the high mutation detection rate, in a small group of haemophilia A patients, using current screening methods, no causal mutation in F8 can be detected. In such cases, the causal mutation might be in the non-coding sequences of F8.

Aim: Rarely, mutations in non-coding sequences reveal a pivotal role.