Congenital Factor VII Deficiency in Children at Tertiary Health Care Facility in Pakistan

Analysis of clinical manifestations and molecular pathogenesis of six patients with hereditary blood coagulation factor VII deficiency

BACKGROUND

Hereditary blood coagulation factor VII (FVII) deficiency is a rare hemorrhagic disorder inherited in an autosomal recessive pattern, involving variants in the gene encoding FVII (F7). The sites and types of F7 mutations could influence the coagulation activity of plasma FVII (FVII: C) and the severity of hemorrhage symptoms. However, the specific molecular mechanisms of FVII deficiency are still unclear.

OBJECTIVE

To analyze clinical manifestations and coagulation functions of six patients of hereditary FVII deficiency and explore specific molecular mechanisms of the disease.

METHODS

We detected coagulation functions including prothrombin time (PT), activated partial thromboplastin time (APTT), PT mixing study and FVII: C. Then genomic DNA of six patients was sequenced through whole exome sequencing (WES). Furthermore, we analyzed and predicted conservatism of the amino acid mutation sites, pathogenicity of mutations and structures of the mutated proteins by bioinformatics tools.

RESULTS

Five patients presented as asymptomatic while only one female experiencing intermittent epistaxis. PT was prolonged and corrected to reference range, and FVII: C was significantly decreased in all patients. Nine mutations were identified, of which three (c.1261delA, c.362G>A and c.227A>G) were reported for the first time. The mutation (c.1261delA) triggered nonsense-mediated mRNA decay (NMD) mechanism, resulting in degradation of abnormal mRNA. The mutation (c.362G>A) might disrupt formation of disulfide bond, affecting normal folding of functional domain. Moreover, protein modeling revealed the formation of a new hydrogen bond. Using ProtScale to analyze the hydrophobicity of the mutation (c.227A>G), it was clear that hydrophobicity of amino acids was enhanced.

CONCLUSION

We have identified three novel mutations and performed analysis that might illuminate the molecular pathogenesis of hereditary coagulation FVII deficiency.

Diagnosis and treatment discussion of congenital factor VII deficiency in pregnancy: A case report

BACKGROUND

Congenital factor VII deficiency (FVIID) is a rare autosomal recessive genetic disorder. The clinical manifestations of this deficiency vary greatly. Predicting the risk of bleeding during and after childbirth of pregnant women with congenital FVIID is difficult. Recombinant factor VIIa is the most common replacement therapy for FVIID. However, no unified diagnosis and treatment plan for pregnant women with congenital FVIID has been established.

CASE SUMMARY

We report the clinical history of a pregnant woman who was considered to have congenital FVIID. Recombinant factor VIIa was prophylactically administered to the pregnant woman at the time of cervical fully opening. She successfully delivered a live infant without any complications, such as postpartum hemorrhage, neonatal abnormalities, and so on.

CONCLUSION

Prophylaxis of recombinant factor VIIa during delivery can effectively reduce the incidence of postpartum hemorrhage among pregnant women with congenital FVIID associated with a high risk of bleeding.

Congenital factor VII deficiency in Iraqi children (Single Centre Experience)

Background and Objective

Factor VII (FVII) deficiency is probably one of the most common of the rare autosomal recessive coagulation disorders, with an estimated prevalence of l: 500000. All age groups can be affected with FVII deficiency. This study aimed to describe the demographic parameters, symptomatology, hemostatic values and the outcome of FVII deficiency.

Methods

This is a retrospective descriptive study of patients with congenital FVII deficiency over a period of seven years from (August 2008 to August 2015). The data were collected by reviewing the files for each patient diagnosed with FVII deficiency. Surgical interventions, complications and follow up visits were recorded.

Results

Twenty-four patients were included in this study, 17 females and seven males, below one year was the most common age at presentation. More than half of patients (58.3%) were diagnosed within six months of symptoms onset. The majority of patients had severe phenotype. The most common symptom was epitaxis (41.7%). Five out of 10 patients with FVII level < 1% have either mild to moderate phenotype of the disease without complications; while six out of 14 patients with FVII > 1% had at least one episode of severe bleeding. Three patients had hepatitis C; all were treated by blood products before the introduction of recombinant FVII in Iraq. The outcome of most patients (75%) was normal without complications at time of study.

Conclusion

Clinical manifestations of FVII deficiency are variable and they are not necessarily correlated to the FVII level.

Novel IVS7+1G>T mutation of life-threatening congenital factor VII deficiency in neonates: A retrospective study in China

In neonates, congenital factor VII deficiency (FVIID) is characterized by central nervous system bleeding and gastrointestinal hemorrhage, often resulting in poor prognosis and high mortality.To improve understanding of FVIID in neonates in Asia, we retrospectively analyzed the clinical manifestations, diagnosis, treatment, clinical course, and genetic diagnosis of 2 cases of neonatal FVIID in the Department of Neonatology, Guangzhou Women and Children's Medical Center, Guangzhou, China, from January 2007 to December 2017 and performed a review of the relevant literature.Both neonates were female and presented with severe gastrointestinal tract and intracranial hemorrhage. The laboratory findings were characterized by repeated and non-vitamin K1-dependent prolonged of the prothrombin time (PT), Factor VII (FVII) activity was 1.5% and 3%, respectively. Both neonates died of severe intracranial hemorrhage, at 31 days and 6 months after birth, respectively. Gene sequencing results revealed a homozygous mutation in the FVII gene splice site (IVS7+1G>T) in both cases. Upon review of relevant literature published since 1996, we identified 19 cases of neonatal FVIID. The patients were full-term neonates with onset of symptoms mostly within 7 days after birth (73.7%), which included gastrointestinal bleeding (blood stool, vomiting blood; 31.6%), nervous system signs (drowsiness, convulsions, poor response; 26.3%), severe intracranial hemorrhage (84.2%), significantly prolonged PT with significantly decreased FVII activity (89.5%), high mortality, and disability (68.4%). Gene sequencing was performed in 9 of the 19 children evaluated and revealed a mutation in the FVII gene in all cases.FVIID can be clinically diagnosed based on the presence of prolonged PT that is difficult to correct and significantly decreased FVII activity (≤5%). As mutations in some sites are associated with severe bleeding, genetic diagnosis represents a useful tool for prenatal diagnosis of FVIID. In brief, we should pay great attention to the FVIID onset of the neonatal period, although it is rare but result in life-threatening bleeding with poor prognosis.