Hereditary coagulation factor VII deficiency caused by novel compound heterozygous mutations c.572-1G>A and c.1037A>C in a Chinese pedigree.

Hereditary coagulation factor VII (FVII) deficiency is a rare autosomal recessive bleeding disorder. The aims of this study were to identify and verify the pathogenic mutation sites in a family with hereditary coagulation FVII deficiency, and preliminarily explore the underlying mechanisms. We identified a novel combination of compound heterozygous mutations, c.572-1G>A and c.1037A>C in F7 gene, associated with FVII deficiency. The splice site mutation c.572-1G>A led to a truncation, resulting in the loss of the essential catalytic domain of the FVII protein. The c.1037A>C missense mutation has not been previously reported. Our study revealed that this mutation leads to steric hindrance between residues, causing significant changes in the energy and structure of the FVII protein, ultimately affecting its function. These changes disrupt the normal function of the FVII protein, accelerating the development of inherited FVII deficiency. Moreover, the mRNA expression of the F7 gene and the protein expression of the FVII antigen (FVII: Ag) were significantly lower in the proband, as well as in the proband's parents, compared to the healthy control (P<0.05). Our findings not only elucidate the genetic underpinning of FVII deficiency in the family studied but also contribute a new mutation to the known disease spectrum, potentially assisting in future diagnostic and therapeutic approaches.

[Congenital Fâ ¦ Deficiency Associated with a Novel Mutation in F7 Gene].

OBJECTIVE: To identify the genetic mutation of coagulation factor Ⅶ ( F7) gene in a pedigree with coagulation factor Ⅶ (FⅦ) deficiency and explore the molecular pathogenesis. METHODS: The prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), D-dimer (DD), fibrin degradation products (FDP) and coagulation factor Ⅶ activity (FⅦ:C) of the proband and her family members were detected by Sysmex-CS5100 analyzer. All exons and exon-intron boundaries of the F7 gene were amplified by PCR followed by direct sequencing. The detected mutation was confirmed by reverse sequencing. The ClustalW software was used to analyze the conservatism of the mutant site. Pathogenicity of the mutation was assessed with Mutation Taster and PolyPhen-2 online bioinformatics software. Structure of the mutant protein was analyzed using Swiss-PdbViewer software. RESULTS: The results of routine coagulation tests showed that PT of the proband was markedly extended to 42.5 s, and her FⅦ:C significantly reduced to 2%. The FⅦ:C of her grandmother, mother and sister had slightly reduced to 49%, 51%, and 42%, respectively. These coagulant parameters of her father were within the normal range. Genetic analysis reveled a heterozygous G>A change at cDNA 646 in exon 6 of F7 gene in the proband, resulting in a replacement of glycine at 156 of FⅦ catalytic region with serine (p.Gly156Ser). The sequencing results of other exons and exon-intron boundaries of her F7 gene were normal. The proband's grandmother, mother and sister were all the carriers of this missense mutation except her father. Bioinformatics analysis showed that the p.Gly156Ser mutation caused polarity change of the amino acid at this site and formation of side chains, leading to increase of protein instability, which may affect catalytic activity of structural domain. Meanwhile, both Mutation Taster and PolyPhen-2 online bioinformatics software also predicted the pathogenicity of this missense mutation with high scores. CONCLUSION: The heterozygous p.Gly156Ser mutation is the direct cause of the reduced FⅦ in this proband.

[Analysis of three Chinese pedigrees affected with Hereditary factor â ¦ deficiency due to compound heterozygous variants of F7 gene].

OBJECTIVE: To analyze the types of genetic variants and clinical characteristics of three Chinese pedigrees affected with Hereditary coagulation factor Ⅶ (FⅦ) deficiency. METHODS: Three pedigrees who had visited the First Affiliated Hospital of Wenzhou Medical University between December 2021 and October 2022 were selected as the study subjects. Prothrombin time (PT), activated partial thromboplastin time (APTT) and FⅦ activity (FⅦ:C) were measured in the three probands and their pedigree members. All exons and their flanking sequences were analyzed by direct sequencing, and candidate variants were verified by reverse sequencing. The corresponding variant loci in the family members were also analyzed. ClustalX-2.1-win was used to analyze the conservation of the variant loci. Varcards and Spcards online software was used to predict the pathogenicity of the variants. Pymol software was used to analyze the changes in protein structure and molecular forces. RESULTS: Three cases of hereditary FⅦ deficiency were found to have decreased FⅦ:C, prolonged PT and normal APTT. Genetic analysis identified a total of four genetic variants, and all three probands had harbored compound heterozygous variants of the F7 gene, including p.Cys389Gly and p.His408Gln in proband 1, p.Cys389Gly and IVS6+1G>T in proband 2, and IVS6+1G>T and IVS1a+5G>A in proband 3. Conservation analysis showed that both the p.Cys389 and p.His408 loci are highly conserved among orthologous species. Analysis with Varcards and Spcards software showed that these variants were pathogenic. Protein modeling analysis showed that the p.Cys389Gly and p.His408Gln variants may result in altered protein structures and changes in hydrogen bonds. CONCLUSION: The clinical manifestations of the three FⅦ-deficient probands may be attributed to the compound heterozygous variants of p.Cys389Gly/p.His408Gln, p.Cys389Gly/IVS6+1G>T and IVS6+1G>T/IVS1a+5G>A of the F7 gene. The combination of the three compound heterozygous variants was unreported previously.

The identification of a novel compound heterozygous mutation in hereditary human coagulation factor VII deficiency following a bamboo leaf green snake bite.

Hereditary factor VII (FVII) deficiency is an uncommon autosomal recessive disorder associated with mutations in the F7 gene, and laboratory investigations usually reveal isolated prolongation in prothrombin time (PT)/international normalized ratio (INR). Venom-induced consumptive coagulopathy (VICC) is distinguished by the activation of the coagulation pathway, which is triggered by procoagulant toxins in snake venom. Diagnosing snakebites in patients with hereditary FVII deficiency presents a challenge because prolonged time PT/INR is considered the most valuable diagnostic method for VICC. Therefore, it is possible that certain patients may not promptly receive an accurate diagnosis of hereditary FVII deficiency. We present a pedigree featuring hereditary FVII deficiency, which was diagnosed through Sanger sequencing, following a bamboo leaf green snake bite.

Genetic Landscape of Factor VII Deficiency: Insights from a Comprehensive Analysis of Pathogenic Variants and Their Impact on Coagulation Activity.

Congenital factor VII (FVII) deficiency is a rare genetic bleeding disorder characterized by deficient or reduced activity of coagulation FVII. It is caused by genetic variants in the F7 gene. We aimed to evaluate the rate of detection of pathogenic variants in the F7 gene in a large group of patients with FVII deficiency and investigate the correlations between the F7 genotype and FVII activity (FVII:C). Moreover, the influence of the common genetic variant rs6046: c.1238G>A; p.(Arg413Gln), designated as the M2 allele, on FVII:C was investigated. Genetic analysis of the F7 gene was performed on 704 index patients (IPs) using either direct Sanger- or next-generation sequencing. Genetic variants were detected in 390 IPs, yielding a variant detection rate (VDR) of 55%. Notably, the VDR exhibited a linear decline with increasing FVII:C levels. We identified 124 genetic variants, of which 48 were not previously reported. Overall, the frequency of the M2 allele was considerably higher in patients with mild deficiency (FVII:C > 20 IU/dl). Furthermore, IPs lacking an identified pathogenic variant exhibited a significantly higher prevalence of the M2 allele (69%) compared to IPs with a disease-causing variant (47%). These results strongly support the association of the M2 allele with decreased FVII:C levels. This study shows the utility of FVII:C as a predictive marker for identifying pathogenic variants in patients with FVII deficiency. The M2 allele contributes to the reduction of FVII:C levels, particularly in cases of mild deficiency.

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.

Factor VII deficiency: a rare genetic bleeding disorder in a 7-year-old child: a case report.

BACKGROUND: Factor VII deficiency is a rare inherited bleeding disorder that has similar clinical presentation to hemophilia. CASE REPORT: A 7-year-old male child of African origin experienced recurrent nasal bleeding since 3 years of age and recurrent swelling of the joints that was remarkable at the age of 5-6 years. He received multiple blood transfusions and has been managed as a patient with hemophilia until he presented to our facility. Reviewed evaluation of the patient revealed abnormal prothrombin and normal activated partial thromboplastin time, FVII analysis showed activity level of less than 1%, and the diagnosis of FVII deficiency was made. The patient was treated with fresh frozen plasma, vitamin K injection, and tranexamic tablets. CONCLUSION: Even though factor VII deficiency is an extremely rare bleeding disorder, it does occur in our setting. This case highlights the need for clinicians to consider this condition when faced with challenging patients presenting with bleeding disorders.

Structural and functional characterization of novel F7 mutations identified in Chinese factor VII-deficient patients.

Hereditary factor VII (FVII) deficiency is a rare recessive bleeding disorder with an estimated prevalence of 1/500 000. We had investigated 50 unrelated Chinese patients with FVII deficiency and identified, in total, 25 mutations, including 18 missense mutations and 5 splicing mutations, on the F7 gene. The nucleotide transition c.1224T>G (p.His408Gln) in exon 9 constitutes a hotspot of mutation, with 19 patients harbouring this genetic variance. Few patients were homozygous or compound heterozygous for deleterious mutations, such as non-sense mutations, large insertion or deletions, indicating that complete deficiency of FVII may not be compatible with life. The eight novel mutations identified in the study, including one small deletion (p.Glu49GlyfsTer101), three type I missense mutations, p.Cys238Phe, p.Gly420Asp, p.Ala252Val and four type II missense mutations, p.Val336Met, p.Ser342Gly, p.Gly432Ser and p.Ile213Asn, were further analysed by in vitro expression and functional studies. The laboratory phenotype and structural analysis confirmed the functional consequence of p.Ile213Asn mutation involving cleavage and activation site. The molecular dynamic simulations and binding energy calculations along with functional probing of p.Gly432Ser mutation revealed the critical role of residue Gly432 in the binding between activated factor VII (factor VIIa) and tissue factor.

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.

Molecular spectrum of inherited FVII deficiency in North India revealed a recurrent variant with a founder effect.

INTRODUCTION: Inherited Factor VII (FVII) deficiency is commonest among the rare bleeding disorders. A small number of patients present in infancy with severe bleeding, and many may remain asymptomatic but detected before surgery/invasive procedures. Genetic testing may be helpful in predictive testing/prenatal diagnosis in severe cases. AIM: Characterisation of clinical and genotypic spectrum of patients with inherited FVII deficiency. METHODS: Retro-prospectively, 35 cases with prolonged prothrombin time and FVII activity (FVII:C) <50 IU/dl were subjected to targeted resequencing. After in-silico analysis, variant/s were validated by Sanger sequencing in index cases and family members. Haplotype analysis was done for F7 polymorphisms. RESULTS: Severe FVII deficiency was found in 50% of patients (FVII:C ≤1 IU/dl), and 42.9% were asymptomatic. Clinical severity assessment revealed 17% severe, 17% moderate and 22.9% patients with mild bleeds. FVII levels ranged from .3 to 38 IU/dl. Molecular analysis revealed variants in 30/35 cases, of which 17 were homozygous, 10 were compound heterozygous and 3 were heterozygous. Twelve genetic variants were identified, one promoter variant c.-30A>C; seven missense (c.215C>G, c.244T>C, c.253G>C, c.904G>A, c.961C>T, c.1109G>T, c.1211G>A), two deletions (c.21delG, c.868_870delATC), and one each of nonsense c.634C>T and splice-site variant c.316+1G>A. Recurrent variants c.1109G>T and c.215C>G were found in 17 and 8 cases, 12 of the former cases were homozygous. They had the same haplotype, indicating the founder effect in North Indians. CONCLUSION: This is the largest cohort of FVII genotyping from India, confirming heterogeneity in terms of clinical manifestations, FVII activity and zygosity of the variants with a limited genotypic phenotypic correlation.

Hereditary coagulation factor VII deficiency caused by novel compound heterozygous mutations in a Chinese pedigree: A case report.

BACKGROUND: Congenital coagulation factor VII (FVII) deficiency is a rare, autosomal-recessive haemorrhagic disorder with an estimated incidence of 1:500,000. This disorder is caused by mutations in the F7 gene. CASE DESCRIPTION: Here, we report a pedigree of congenital FVII deficiency. The proband was a 30-year-old female with severely low FVII activity and a history of menorrhagia and epistaxis since her childhood who was subsequently diagnosed with congenital compound heterozygous FVII deficiency. A genetic study revealed a novel combination of compound heterozygous mutations (c.64G 〉 A, p.Gly22Ser and c.1027G 〉 A, p.Gly343Ser). Her father and older son had the c.64G 〉 A, p.Gly22Ser (heterozygous) mutation. Her mother and younger son had the c.1027G 〉 A, p.Gly343Ser (heterozygous) mutation. The predicted results of PolyPhen-2 and MutationTaster indicated that these mutations were probably damaging and disease-causing, respectively. CONCLUSION: In this study, we identified a novel combination of genetic mutations that could expand the mutant library and help in elucidating the pathogenesis of hereditary human coagulation FVII deficiency. A novel combination of compound heterozygous mutations was reported for the first time in Chinese individuals.

Factor VII deficiency in China: Phenotype, genotype and current status of management.

Congenital factor VII (FVII) deficiency is a rare bleeding disorder characterised by a wide molecular and clinical heterogeneity. We investigated the clinical phenotype of 193 patients and F7 genotype of 55/193 patients with FVII deficiency throughout China and showed their current status of management. The most frequent bleeding symptoms were epistaxis (44.6%), cutaneous (38.9%), oral cavity (40.4%) bleeding and menorrhagia (44.3% of females of reproductive age). Fatal central nervous system bleeding and disabling joint bleeding occurred in three patients each. The majority of patients (89.6%) had FVII activity (FVII:C) ≤10% and the proportion of symptomatic patients in this group (79.8%) was significantly higher than that in the groups with FVII:C >10%-25% (41.7%) and >25%-50% (37.5%) (χ2 = 13.641, p = 0.001). Major bleeds occurred only in patients with FVII:C ≤10%. In total 55 patients underwent genotype analysis: most variants were missense (62.5%) and most patients had homozygous/compound heterozygous (85.4%) variants. Prothrombin complex concentrates (72.4%) were the most frequently used on-demand replacement therapy. Prophylaxis before delivery decreased the risk of postpartum bleeding in women (χ2 = 69.243, p = 0.000). Our study provides useful information on the phenotype, genotype and current status of FVII-deficiency patients management and may promote further exploration and care of this population in the future.

Factor VII Deficiency Due to Compound Heterozygosity for the p.Leu13Pro Mutation and a Novel Mutation in the HNF4 Binding Region (-58G>C) in the F7 Promoter.

We investigated the molecular basis of factor VII (FVII) deficiency in a Japanese patient and identified compound heterozygous mutations. Factor VII activity and antigen levels in the patient were less than 5.0% and 6.5% of controls, respectively. All exons, exon-intron boundaries, and the 5' promoter region of F7 from genomic DNA were amplified using polymerase chain reaction (PCR). Sequencing analysis of PCR fragments revealed that the patient was heterozygous for a known T to C substitution at nucleotide position 38, which resulted in the p.Leu13Pro missense mutation (Factor VII Morioka) in the signal peptide region, and a novel mutation in the 5' promoter region (-58G>C). An electrophoretic mobility shift assay showed that the mutation in the promoter region reduced the binding of hepatocyte nuclear factor (HNF). It is presumed that the reduced binding of HNF-4 to the F7 promoter region reduces F7 transcription and thus reduces the synthesis and expression of FVII.

Investigation of a common canine factor VII deficiency variant in dogs with unexplained bleeding on autopsy.

The factor VII (FVII) protein is an integral component of the extrinsic coagulation pathway. Deleterious variants in the gene encoding this protein can result in factor VII deficiency (FVIID), a bleeding disorder characterized by abnormal (slowed) clotting with a wide range of severity, from asymptomatic to life-threatening. In canids, a single FVIID-associated variant, first described in Beagles, has been observed in 24 breeds and mixed-breed dogs. Because this variant is present in breeds of diverse backgrounds, we hypothesized that it could be a contributing factor to unexplained bleeding observed in some canine autopsy cases. DNA was extracted from paraffin-embedded tissue samples from 67 anticoagulant-negative autopsy cases with unexplained etiology for gross lesions of hemorrhage. Each dog was genotyped for the c.407G>A (F71) variant. Experimental controls included 3 known heterozygotes and 2 known homozygotes for the F71 variant, 2 normal dogs with known homozygous wild-type genotypes (F7WF7W), and 5 dogs with bleeding at autopsy that tested positive for anticoagulant rodenticide and were genotyped as F7WF7W. All 67 cases tested homozygous for the wild-type allele, indicating that the common FVIID variant was not responsible for the observed unexplained bleeding. Our work demonstrates the usefulness of retrospective studies utilizing veterinary diagnostic laboratory databases and tissue archives for genetic studies. In the case of FVIID, our results suggest that a singular molecular test for the F71 variant is not a high-yield addition to postmortem screening in these scenarios.

Mutations of TFPI-binding exosites on factor VII cause bleeding phenotypes in factor VII deficiency.

Tissue factor (TF) pathway inhibitor (TFPI) is a Kunitz-type anticoagulation protein that inhibits activated factor VII (FVIIa)/TF complex. Incidentally, many different F7 gene variants, including TFPI-binding exosite mutations, have been reported in patients with congenital FVII deficiency and clinical bleeding variabilities. Here, TFPI-binding exosites (R147 and K192) on FVII zymogen were selectively disrupted to understand their roles in the pathogenesis of bleeding phenotypes. Expression of recombinant FVII variants (R147A, K192A, and R147A/K192A) demonstrated markedly reduced secretion of FVII owing to intracellular retention in the endoplasmic reticulum, as demonstrated by upregulation of the unfolded protein response genes in all FVII variants. FVII variants showed a similar FVII activation pattern and FVIIa amidolytic activity than FVII wild-type (WT). In contrast to FVII activation, R147A and K192A showed a 90% reduction in FX activation relative to WT, whereas the R147A/K192A variant demonstrated a 99% decrease in FX activation. The clotting time was markedly prolonged with R147A and K192A than WT, and no FVII coagulant activity was detected in R147A/K192A. In addition, the thrombin generation assay revealed a significant prolongation of lag time in all FVII variants. Our study explains how mutations of TFPI-binding exosites of FVII can lead to bleeding phenotypes in individuals carrying these aberrancies.

Phenotypic and genotypic characterization of two factor VII deficiency patients from southeastern China.

The congenital factor VII deficiency (FVIID) is a rare autosomal recessive haemorrhagic disease caused by mutations in the F7 gene. The aim of this study was to identify the mutations causing FVII deficiency and explain the genotype-phenotype association in two unrelated Chinese patients. Mutation detection was conducted by sequencing the whole F7 gene coding exons, exon-intron boundaries and the untranslated regions of 3' and 5'. Then, the genetic information was analyzed to predict the structures of the mutated proteins. A total of four different mutations were detected, including three missense mutations (c.64G>A, c.286A>G, and c.722C>A, predicting p.Gly22Ser, p.Arg96Gly, p.Thr241Asn, respectively) and one insertion mutation (c.204_205insCGGC, predicting p. Leu68Argfs ∗ 37), among which two were reported for the first time (p.Arg96Gly, p.Leu68Argfs ∗ 37). Multiple sequence alignments of FVII protein revealed that the residues p.Arg96 and p.Thr241 were highly conserved. The novel missense mutation p.Arg96Gly was determined as damaging with online software Polyphen-2 and SIFT. We investigated two asymptomatic patients diagnosed with severe FVII deficiency and identified two novel mutations (the mutation p.Arg96Gly and p.Leu68Argfs ∗ 37). Identification of the F7 mutations was important for genetic counseling and accurate prediction of the inheritance pattern.

Clinical phenotype and F7 gene genotype in 40 Tunisian patients with congenital factor VII deficiency.

Congenital factor VII (FVII) deficiency is an autosomal recessive bleeding disorder characterized by a weak phenotypic and genotypic correlation. This study aimed to determine the genetic alterations of 40 Tunisian patients and to evaluate their relationships with the collected clinical and biological data. Forty FVII-deficient Tunisian patients have been included in this study. First, diagnosis of the FVII deficiency was made on the basis of FVII coagulant activity (FVII:c) levels performed using the prothrombin time assay. Then, clinical and anamnesis data were set up and filed out from the regional registry of bleeding disorders and the medical file of each patient. Finally, genetic alterations were determined by direct sequencing of the coding regions, intron/exons boundaries of the F7 gene. Clinical heterogeneity was noticed, and the direct sequencing allowed the identification of 13 F7 gene mutations of which one was a novel mutation. The clinical manifestations are variably associated with FVII activity FVII:c levels. Lack of relations between severity of clinical manifestations and genotypes was observed; however, a relationship between the nonpathogeneous mutations and clinical phenotypes was noticed. A wide phenotypic inter-individual variability was detected, which suggests the presence of other extra-genetic components influencing the expressivity of the deficiency.