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.

A novel Cys328-terminator mutant implicated in severe coagulation factor XIII deficiency: a case report.

BACKGROUND: Factor XIII (FXIII) deficiency is an extremely rare bleeding disorder that is commonly due to mutations in the FXIIIA subunit gene (F13A1), and it has been reported to have a prevalence of one per 2 million. We describe a new genetic variant in the F13A1 gene that caused a patient to suffer from lifelong hemorrhagic diathesis. CASE PRESENTATION: We evaluated a 20-year-old female with umbilical cord bleeding after birth, an intracerebral hemorrhage at age 6, and other bleeding episodes, including hematuria and cephalohematoma, who suffered from a lifelong hemorrhagic diathesis. The clot solubility test showed that the clot of the patient was dissolved in urea solution at 10 h. Genetic testing identified a novel homozygous mutation, c.984C > A(p. Cys328stop), resulting in a premature stop codon in exon 8 of the F13A1 gene. The results obtained with ClusterX software showed that Cys328 of exon 8 in the F13A1 gene is highly conserved among species. CONCLUSION: We reported a novel homozygous mutation in the F13A1 gene in a factor XIII (FXIII)-deficient patient, which adds a new point mutation to the mutant library. In this paper, we discuss other aspects of the disease, including laboratory examination, homogeneous sequence alignment and molecular modeling.

Hereditary protein C deficiency caused by novel compound heterozygous mutants in a Chinese pedigree: A case report.

Purpura fulminans (PF) is a neonatal presentation of homozygous or compound heterozygous protein C (PC) deficiency; infants who are diagnosed with it are determined to have a major defect in coagulation regulation which is associated with undetectable levels of PC. We report a pedigree who suffered from the hereditary PC deficiency with compound heterozygous mutants; genetic analysis revealed compound heterozygous mutations of 262 G > T(Asp88Tyr) and 400 + 5G > A that were identified in the proband; moreover, Asp88Tyr and 400 + 5G > A were also detected in the father and the mother, respectively. A bioinformatics analysis revealed 262 G > T is probably damaging, and structural analysis indicated a possible mechanism for the functional impairment of PC in this pedigree.

A novel fibrinogen variant in a Chinese pedigree with congenital dysfibrinogenemia caused by FGA P. Arg38Thr mutation: A case report.

RATIONALE: Congenital dysfibrinogenemia (CD) is characterized by altered functional properties of the fibrinogen; people who suffer from CD often have a low activity of fibrinogen and the mutation in the genomic DNA. PATIENT CONCERNS: A 6-year-old child was examined with a low activity of fibrinogen measured by Von Clauss method and PT-derived method which indicated a normal level of fibrinogen; this abnormality was also detected in her mother. The genomic DNA of all the family members was extracted, and all exons of 3 fibrinogen genes which encode fibrinogen alpha chain (FGA), fibrinogen beta chain (FGB), and fibrinogen gamma chain (FGG) were amplified by polymerase chain reaction (PCR), in addition, sanger sequencing, homologous sequence alignment and bioinformatics software were performed for the further analysis. DIAGNOSES: CD in this pedigree is associated with c.113G>C in the exon 2 of FGA which caused Arg38Thr mutation. OUTCOMES: The child and her mother showed a low plasma concentration of fibrinogen measured by Von Clauss method, whereas a normal result measured by PT-derived method; finally, c.113G>C in the exon 2 of FGA was detected in the pedigree which caused Arg38Thr mutation and it is the first report on a pedigree with CD caused by AαArg38Thr. LESSONS: This case gives us the lesson that not all patients with CD showed typical symptoms and laboratory test results; the result of fibrinogen concentration and antigen which is tested by Von Clauss method and immunoturbidimetric assay is various according to the condition of each CD patient.