Acute Thrombotic Events in Association With Coronavirus Disease of 2019 Immunization as Initial Presentation of Congenital Factor VII Deficiency

Coagulation factor VII (FVII) deficiency is a congenital disorder with heterogeneous clinical phenotypes ranging from asymptomatic to life-threatening bleeding and/or thrombotic events. We present the case of an adolescent male who developed acute deep and superficial venous thromboses of the upper extremities in the setting of multiple peripheral venous line insertions and shortly after receiving his second coronavirus disease of 2019 immunization dose. A hemostatic work-up revealed low FVII activity levels associated with 4 different FVII genetic variants. We highlight the need to better understand the pathophysiologic mechanisms behind FVII deficiency-associated prothrombotic risk and the role that specific FVII genetic variants may play in the clinical presentation of these patients.

Testing strategies used in the diagnosis of rare inherited bleeding disorders

INTRODUCTION

Rare Bleeding Disorders have a low population prevalence and may not be recognized by most clinicians. In addition, knowledge gaps of the indicated laboratory tests and their availability add to the potential for delayed diagnosis or misdiagnosis. The lack of widely available commercial, regulatory body approved esoteric tests limit them to reference laboratories, thus limiting easy access for patients.

AREAS COVERED

A literature search of Pubmed, Medline, Embase and review of international society guidelines was performed. Additional references from published articles were reviewed. A patient-centered approach to recognition and evaluation of RBD is discussed.

EXPERT OPINION

Recognition of RBD relies on obtaining a detailed patient personal and family hemostatic history. Inquiry into a history of involvement of other organ systems is important and if present should lead to suspicion of an inherited platelet disorder or a variant of Ehlers Danlos Syndrome. Multiple factors contribute to the complexity of development of efficient algorithms for diagnostic testing. Limitations in diagnostic sensitivity and specificity of screening tests, diagnostic tests, and esoteric tests further compound the complexity of establishing a diagnosis. Educational efforts focusing on clinician awareness of RBDs and available testing options are vital for optimal management of such patients.

Factor VII Padua in Iran: clinical and laboratory findings of three unrelated patients

The congenital factor VII (FVII) deficiency with an estimated incidence of one per 300 000 is the most common rare congenital bleeding disorder. The heterogeneous clinical pictures, including asymptomatic to life-threatening manifestations, are seen in patients with FVII deficiency. A variety of gene variants throughout the FVII ( F7 ) gene have been reported so far. In this setting, very rare FVII Padua polymorphism provokes an interesting condition in which results of prothrombin time and FVII activity are different based on the thromboplastin sources used in these tests. The current study aimed to report the phenotype and genotyping of patients with Padua variant. During the workup of the laboratory for FVII deficiency for diagnosis of FVII Padua, all patients with FVII deficiency who had prolonged prothrombin time, normal activated partial thromboplastin time, and variable FVII activity results using different sources of thromboplastin were included. Demographic data and clinical findings were recorded. For the molecular study, the F7 gene sequencing was performed using the Sanger sequencing technique. Five patients with FVII Padua and a history of mild-to-moderate bleeding, including easy bruising, epistaxis, gingivorrhagia, and bleeding after surgical challenges (including dental extraction and tonsillectomy), were detected during the study. DNA sequencing revealed a heterozygote CGG to CAG (Arg364Gln) variant in exon 9 at nucleotide position 1091, consistent with the genetic variant of FVII Padua. Timely diagnosis of FVII Padua is vital to avoid unnecessary exposure of patients to replacement therapy.

Thrombotic Events in Homozygotes with a Proven or Highly Probable Arg304Gln Factor VII Mutation (FVII Padua)1): Only Limited Replacement Therapy is Needed in Case of Surgery

OBJECTIVE

To investigate the prevalence of thrombotic events among patients with proven or highly probable homozygosis for the Arg304Gln (Factor VII Padua) defect or compound heterozygosis containing the Arg304Gln mutation.

METHODS

Homozygotes and compound heterozygotes proven by molecular studies to have the Arg304Gln mutation were gathered from personal files and from two PubMed searches. In addition, patients with probable homozygosis on the basis of clotting tests (discrepancies among Factor VII activity levels according to the tissue thromboplastin used) were also gathered.

RESULTS

30 proven homozygotes and 17 probable ones were gathered together with 8 compound heterozygotes. In the latter use, the associated mutation was Cys135Arg (twice), Gly180Arg, Arg304Trp, Arg315Trp, His348Gln, Gly365Cys. The prevalence of venous thrombotic events was 16.6, 11.8 and 11.1 percent, respectively for the three groups of patients. Heterozygotes showed no thrombotic event. The difference for proven homozygotes was statistically significant, while for the other groups only a trend was present.

CONCLUSION

proven homozygous or compound heterozygous patients with the Arg304Gln mutation showed a higher than expected incidence of thrombotic events. The same is true for probable cases gathered only on the basis of clotting tests. These patients, because of their frequent lack of bleeding and for their relatively high prevalence of thrombosis should probably receive only limited replacement therapy in case of surgical procedures.

Factor VII Deficiency: Clinical Phenotype, Genotype and Therapy

Factor VII deficiency is the most common among rare inherited autosomal recessive bleeding disorders, and is a chameleon disease due to the lack of a direct correlation between plasma levels of coagulation Factor VII and bleeding manifestations. Clinical phenotypes range from asymptomatic condition—even in homozygous subjects—to severe life-threatening bleedings (central nervous system, gastrointestinal bleeding). Prediction of bleeding risk is thus based on multiple parameters that challenge disease management. Spontaneous or surgical bleedings require accurate treatment schedules, and patients at high risk of severe hemorrhages may need prophylaxis from childhood onwards. The aim of the current review is to depict an updated summary of clinical phenotype, laboratory diagnosis, and treatment of inherited Factor VII deficiency.

Factor VII Deficiency: From Basics to Clinical Laboratory Diagnosis and Patient Management

Factor VII (FVII) deficiency is a rare inheritable bleeding disorder affecting 1/500 000 individuals. Clinical manifestations are heterogeneous, from asymptomatic to severe and potentially fatal bleeding. These clinical manifestations do not correlate well with FVII plasma levels. For this reason, FVII-deficient patient management during surgery or for long-term prophylaxis remains challenging. Laboratory testing for FVII activity is, however, the first-line method for FVII deficiency diagnosis and is helpful for managing patients in combination with clinical history. Additional testing consists of FVII immunoassay and genetic testing. Genetic abnormalities on the FVII gene are heterogeneous and can translate into quantitative or qualitative defects. Some of the latter can react differently with different thromboplastins; this can be misleading for the laboratory as no consensus exists at present on an FVII deficiency diagnosis methodology. Indeed, no single test is able to predict accurately the bleeding risk. This review provides a broad picture of inherited and acquired FVII deficiency with a particular focus on laboratory diagnosis.

Pathogenetic role of Factor VII deficiency and thrombosis in cross-reactive material positive patients

Congenital Factor VII (FVII) deficiency can be divided into two groups: cases of "true" deficiency, or cross-reactive material (CRM) negative and variants that are cross-reactive material positive.The first form is commonly recognized as Type I condition whereas the second one is known as Type II. FVII deficiency has been occasionally associated with thrombotic events, mainly venous. The reasons underlying this peculiar manifestation are unknown even though in the majority of associated patients thrombotic risk factors are present. The purpose of the present study was to investigate if a thrombotic event was more frequent in Type I or in Type II defect.The majority of patients with FVII deficiency and thrombosis belong to Type II defects. In the following paper we discuss the possible role of the dysfunctional FVII cross-reaction material as a contributory cause for the occurrence of thrombosis.

Identification of genetic defects underlying FVII deficiency in 10 patients belonging to eight unrelated families of the North provinces from Tunisia

Inherited factor VII (FVII) deficiency is a rare disorder characterized by a bleeding phenotype varying from mild to severe. To date, more than 200 mutations have been described along the F7 gene encoding for FVII. The aim of this study was the identification of genetic defects underlying FVII deficiency in 10 patients belonging to eight unrelated families of the North provinces from Tunisia. Mutation detection was performed by sequencing the whole F7 gene coding region, exon-intron boundaries and about 400 bp of the promoter region. We identified 5 mutations in five unrelated families; the novel p.F328Y mutation and the reported mutations: p.R304Q, p.M298I, IVS1aG > A and p.G-39G. For the remaining 5 patients we didn’t identified any mutations using PCR/Sequencing protocol. In conclusion, this study represents the first comprehensive molecular series of FVII deficiency affected patients in Tunisia from the North. We will try in the future to continue the molecular study for Tunisian patients from Center and South provinces in order to have a complete idea about the FVII deficiency mutational profile in our country.