OBJECTIVETo investigate the gene defect in a hereditary coagulation factor V (FV) deficiency family.

METHODSThe plasma FV actigen was measured by one-stage clotting assay. The FV antigen was assayed by Biotin-Avidin enzyme linked immunosorbent assay (BA-ELISA). The full length of exon 1 to exon 25 and the 5' untranslated sequence of FV genomic DNA were analyzed by polymerase chain reaction (PCR) and direct sequencing of the amplified fragments, meanwhile the defect was identified by T/A cloning sequencing.

RESULTSThe plasma coagulant activity and amount of FV of the proband were marked deficient (1% and 1.54%, respectively). DNA sequence analysis for the proband revealed a causative mutation in a heterozygous status. It was one base pair deletion in exon 4 at nucleotide 675 inherited from her mother.

CONCLUSIONSA novel mutation in the FV gene was identified in the proband with congenital FV deficiency. The mutation was 675delA in exon 4 resulting in a frameshift and a premature termination codon.

Adolescent ; Blood Coagulation ; Factor V ; analysis ; genetics ; Factor V Deficiency ; blood ; genetics ; Female ; Humans ; Mutation

OBJECTIVE: To explore the genetic basis for a consanguineous pedigree affected with inherited coagulation factor V deficiency. METHODS: Genomic DNA was extracted from peripheral blood samples from the pedigree and subjected to next generation sequencing for screening variants of the F5 gene. Suspected pathogenic variant was verified by using Sanger sequencing. Pathogenicity of the variant was evaluated according to ACMG guidelines. RESULTS: A homozygous frameshifting variant, c.4096delC (p.Leu1366Phefs*3), was identified in the F5 gene in the proband, which was confirmed to be derived from her consanguineous parents. This variant was absent in all databases including 10 000 in-house Chinese exome sequences. Based on the ACMG guidelines, the c.4096delC was predicted to be a pathogenic variant. CONCLUSION A novel pathogenic variant has been identified in the F5 gene in a consanguineous pedigree with inherited coagulation factor V deficiency, which has enriched the spectrum of F5 gene variants.
Consanguinity ; Factor V ; genetics ; Factor V Deficiency ; genetics ; Female ; Genetic Variation ; Humans ; Pedigree

OBJECTIVE: To explore the molecular basis for a pedigree affected with coagulation factor V (FV) deficiency. METHODS: Clinical data of the patient and his family members was analyzed. Targeted capture and next-generation sequencing (NGS) and Sanger sequencing were carried out to detect potential variant of the FV gene. RESULTS: The patient presented with jaundice and prolonged prothrombin time (PT) and activated partial thromboplastic time (APTT). V factor activity measured only 0.1% of the normal level, though the patient had no sign of bleeding. A paternal heterozygous variant c.653T>C (p.F218S) and a maternal heterozygous variant c.3642_3643del (p.P1215Rfs*175) were identified in the FV gene of the patient. His elder brother was a heterozygous carrier of the c.653T>C (p.F218S) variant. c.653T>C(p.F218S) was a known pathogenic variant, while the c.3642_3643del (p.P1215Rfs*175) variant was unreported previously. CONCLUSION Mutations of the FV gene probably underlie the hereditary coagulation factor V deficiency in this patient. NGS combined with Sanger sequencing has detected potential variant with efficiency and provided a reliable basis for clinical and prenatal diagnosis for this family.
Aged ; Factor V ; Factor V Deficiency ; genetics ; Genetic Variation ; Heterozygote ; Humans ; Male ; Mutation ; Pedigree ; Phenotype

OBJECTIVE: To analyze the molecular pathogenesis by analysis of phenotype and gene mutation in families with hereditary coagulation factor V (FⅤ) defect caused by complex heterozygous mutation. METHODS: Plasma pro-thrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), FⅤ procoagulant activity (FⅤ∶C), FⅤ antigen (FⅤ∶Ag), and other related coagulation indexes were detected in the proband and his family members (3 generations 10 people). Using DNA direct sequencing to analyze all exons, flanks, 5' and 3' untranslated regions of F5 genes and the corresponding mutation site regions of family members, the mutation site was confirmed by reverse sequencing．The conservation of mutant amino acids was analyzed by ClustalX-2.1-win software. The PROVEAN and MutationTaster online bioinformatics software were used to predict the effect of mutation on protein function. Protein model and amino acid interaction at mutation sites was analyzed by Swiss-pdbviewer software. RESULTS: The PT and APTT of the proband were significantly prolonged compared with healthy controls (34.2 vs 13.2 s and 119.3 vs 36.0 s), while FⅤ∶C and FⅤ∶Ag extremely reduced (3% and 6%). The PT and APTT of the second-born, the third son, daughter, and grandson of the proband were slightly prolonged, and the FⅤ∶C and FⅤ∶Ag decreased to varying degrees. The related coagulant parameters of other family members were within normal range. Genetic analysis revealed that the proband had a c.911G>A heterozygous missense mutation on the exon 6 lead to p.Gly276Glu, and a c.5343C>G heterozygous missense mutation on the exon 16 lead to p.Ser1781Arg of the proband. The second-born, the third son, and grandson of the proband carry p.Gly276Glu heterozygotes, and the daughter carries p.Ser1781Arg heterozygotes, while the other family members were wild-type. The results of conservative analysis indicated that p.Gly276 and p.Ser1781 were highly conserved in homologous species. The two bioinformatics software predicted the same results, PROVEAN (score -6.214 and -12.79) indicated that the compound heterozygous mutation was a harmful mutation; MutationTaster (score 0.976 and 0.999) suggested that these mutations might cause corresponding disease. p.Gly276Glu protein model analysis showed that, the Glu side chain was prolonged and the molecular weight became larger, which would increase the steric hindrance between it and the surrounding amino acids, affect the normal local folding of the FⅤ protein, and eventually lead to the decrease of protein activity and content. This paper can not provide analysis of the spatial structure of p.Ser1781Arg mutant protein because of the lack of X ray 3 D structure file of FⅤ exon 16. CONCLUSION The new compound heterozygous mutations (p.Gly276Glu and p.Ser1781Arg) identified in this study are the main reasons for the decrease in the FⅤ level of the family, among which p.Ser1781Arg is rarely reported at home and abroad.
Factor V/genetics* ; Family ; Genotype ; Heterozygote ; Humans ; Mutation ; Pedigree ; Phenotype

OBJECTIVETo explore the molecular pathogenesis for a pedigree affected with coagulation factor Ⅴ (FⅤ) deficiency.

METHODSProthrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), coagulation factor Ⅱ activity (FⅡ: C), FⅤ activity (FⅤ: C), coagulation factor Ⅶ activity (FⅦ: C), and coagulation factor Ⅹ activity (FⅩ: C) were determined with a STAGO automatic coagulometer. FⅤ antigen (FⅤ: Ag) was detected with enzyme linked immunosorbent assay (ELISA). All exons and their flanking regions, and 5' and 3' untranslated regions of the F5 gene were analyzed by direct sequencing. Suspected mutation was verified by reverse sequencing as well as testing of family members. ClustalX software was used to analyze the conservative property of the mutation sites. PROVEAN and MutationTaster online software was used to predict the effect of the mutation on the protein function. Swiss-pdbViewer was used to analyze the protein model and interaction of amino acids.

RESULTSThe PT and APTT of the proband were slightly prolonged to 15.2 s and 41.8 s, respectively. And the FⅤ: C and FⅤ: Ag measured 55% and 62%, respectively. The FⅤ: C and FⅤ: Ag of his father and son were decreased to various extent (60%, 65% and 31%, 40%, respectively). A c.911G>A heterozygous mutation (Gly276Glu) was detected in exon 6 of the proband, for which her father and son were heterozygotes. The same mutation was not found in her mother, brother and husband. Conservation analysis showed that the Gly276 is highly conserved across various species. By bioinformatic analysis, the PROVEAN (scored -6.214) indicated Gly276Glu was harmful, and MutationTaster (scored 0.976) suggested that it is pathogenic. Model analysis suggested there are two hydrogen bonds between Gly276 and Ile298 in the wild type protein. When Gly276 was replaced by Glu276, the original hydrogen bond did not change, but the side chain of Glu was extended, which added steric hindrance with the surrounding amino acids, which resulted in decreased protein stability.

CONCLUSIONThe heterozygous c.911G>A (Gly276Glu) mutation of the F5 gene probably underlies the decreased level of FⅤin the proband.

Adult ; Computational Biology ; Factor V ; chemistry ; genetics ; Factor V Deficiency ; genetics ; Female ; Humans ; Male ; Middle Aged ; Mutation ; Pedigree ; Phenotype

Combined deficiency of factor V and VIII (F5F8D) is a rare, autosomal recessive disorder caused by mutations of either lman1 or mcfd2. To identify mutations of these two genes in a Chinese F5F8D family, the samples of peripheral blood were collected from the proband and her parents. Coagulation tests were carried out, including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), fibrinogen (Fg) and coagulate activity of FV, FVIII (FV:C, FVIII:C). The genomic DNA was extracted, then all the exons and intron/exon boundaries of these two genes were amplified by polymerase chain reaction (PCR). The products were finally analyzed by direct sequencing. The results showed that the proband's APTT, PT, TT, Fg, FV:C and FVIII:C were 82.2 sec, 19.6 sec, 18.6 sec, 2.9 g/L, 7.1% and 18.7% respectively, while those parameters of the parents were all within the normal range. Two pathogenic mutations were identified in lman1 gene of the proband: one was the heterozygous c.912_913insA in exon 8 resulting in a frameshift of p.Glu305fsX20; the other was the heterozygous c.1366C > T in exon 11 resulting in p.Arg456X. The proband's father and mother were heterozygous for c.1366C > T and c.912_913insA respectively. It is concluded that F5F8D of the proband is caused by a novel compound heterozygous mutation of the lman1 gene, which has never been reported.
Child ; Exons ; Factor V ; genetics ; Factor V Deficiency ; etiology ; genetics ; Factor VIII ; genetics ; Female ; Hemophilia A ; etiology ; genetics ; Heterozygote ; Humans ; Mannose-Binding Lectins ; genetics ; Membrane Proteins ; genetics ; Mutation ; Pedigree

OBJECTIVETo investigate the interaction of deficiency in thrombosis-related gene in a mouse model.

METHODSTo generate mice carrying mutations in alpha-galactosidase A (Gla) and factor V Leiden (Fvl) and analyze the phenotypes, namely, tissue fibrin deposition and thrombus formation in organs.

RESULTSFibrin deposition in organs of mice carrying both mutations in Gla and Fvl was significantly increased compared with that in mice with single mutaton: [Gla(-/0) Fv(Q/Q)+Gla(-/-)Fv(Q/Q)] vs.[Gla(-/0)Fv(+/+)]=(0.28+/-0.03)% vs.(0.07+/-0.007)%, P<0.01; [Gla(-/0)Fv(Q/Q)+Gla(-/-)Fv(Q/Q)] vs.[Gla(+/0)Fv(Q/Q)+Gla(+/+)Fv(Q/Q)]=(0.28+/-0.03)% vs.(0.11+/-0.02)%, P< 0.01. Meanwhile, the number of thrombi on organ sections of mice carrying both mutations in Gla and Fvl was significantly increased compared with the single mutation carrier: [Gla(-/0)Fv(Q/Q)+Gla(-/-)Fv(Q/Q)] vs.[Gla(-/0)Fv(+/+)]=1.9+/-0.7 vs. 0.0+/-0.0, P<0.05; [Gla(-/0)Fv(Q/Q)+Gla(-/-)Fv(Q/Q)] vs. [Gla(+/0)Fv(Q/Q)+Gla(+/+)Fv(Q/Q)]=1.9+/-0.7 vs. 0.3+/-0.1, P<0.05.

CONCLUSIONThese observations demonstrated that there was synergistic effect in Gla and Fvl deficiency in mice. It suggested that there could be a combination of GLA deficiency and FVL or other thrombosis-related gene defect in patients with genetic severe early-onset thrombosis.

Animals ; Factor V ; genetics ; Fibrin ; metabolism ; Immunohistochemistry ; Mice ; Mutation ; Thrombosis ; genetics ; metabolism ; alpha-Galactosidase ; genetics

OBJECTIVETo identify gene mutations involved in five cases of inherited factor V (FV) deficiency.

METHODSActivity of FV was determined by one-stage clotting assay using FV-deficiency plasma, and FV antigen by an ELISA assay. All the exons and exon-intron boundaries of FV gene were amplified by PCR and then DNA sequencing. Restriction enzyme analysis was used to analyze the probands, their family members and healthy volunteers.

RESULTSBoth activity and antigen of FV in the 5 patients were extremely lower compared with that of normal mixed plasma. Six mutations were identified in these 5 patients, G69969T (G2079V), C45533T (R712Ter), C46796T (R1133Ter), G45366A (C656Y), C46253T (R952C) and G16088C (D68H), the latter three were novel mutations reported for the first time and the C46253T (R952C) was the first missense mutation reported in B domain. The result of sequencing or restriction enzyme analysis showed that the three novel missense mutations were not caused by single nucleotide polymorphisms.

CONCLUSIONGene mutations in 5 type I inherited FV deficiency of patients including 2 nonsense mutations and 4 missense mutations identified which led to the instability of FV protein and the reducing of FV: Ag in the plasma.

Adolescent ; Adult ; Child ; DNA Mutational Analysis ; Exons ; genetics ; Factor V ; genetics ; metabolism ; Factor V Deficiency ; blood ; genetics ; Female ; Humans ; Male ; Mutation ; Pedigree ; Phenotype ; Young Adult

OBJECTIVETo provide genetic consulting and prenatal diagnosis for two families with congenital factor V deficiency based on the known mutations of factor V gene (G16088C and G69969T).

METHODSChorionic DNA was obtained at 12 weeks of gestation and analyzed to exclude maternal cell contamination through microsatellite DNA analysis. It was then amplified with PCR and sequenced to determine the presence of mutations in exons 3 and 23. Factor V activity of the blood was assayed at 22 weeks of gestation and 6 months after birth.

RESULTSThe fetus in case 1 was found to be a heterozygous carrier of the G16088C mutation, for whom factor V activity of the cord blood and peripheral blood were 15% and 53%, respectively. Fetus 2 did not carry the familiar G69969T mutation, for whom the factor V activity of cord blood and peripheral blood has measured 32% and 93%, respectively. Follow-up studies demonstrated that the two infants were both in good health without a tendency for bleeding.

CONCLUSIONIn both cases, the genotypes were consistent with the phenotypes. This is the first report of prenatal diagnosis of congenital factor V deficiency.

Adult ; Base Sequence ; Child ; Factor V ; genetics ; metabolism ; Factor V Deficiency ; diagnosis ; genetics ; Female ; Humans ; Male ; Microsatellite Repeats ; Mutation ; Pregnancy ; Prenatal Diagnosis

OBJECTIVETo screen potential mutation and explore the underlying mechanism for a consanguineous pedigree featuring hereditary coagulation factor Ⅴ (FⅤ) deficiency.

METHODSClinical diagnosis was validated by coagulant parameter assays of prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), FⅤ procoagulant activity (FⅤ:C) and FⅤ antigen (FⅤ:Ag). Potential mutations of the F5 gene in the proband and his family members were analyzed by direct DNA sequencing of PCR products of all exons, exon-intron boundaries and 3', 5' untranslated regions. Suspected mutation was confirmed by reverse sequencing.

RESULTSThe PT and APTT in the proband were significantly prolonged, which measured 23.5 s (reference range 11.8-14.8 s) and 50.5 s (reference range 27.0-41.0 s), respectively. FⅤ activity and FⅤ antigen of the proband were significantly reduced to 8% and <1%, respectively. PT and APTT in the younger sister of the proband were also significantly prolonged (24.1 s and 62.4 s, respectively). Her FⅤ activity and FⅤ antigen were also significantly decreased (7% and <1%, respectively). PT and APTT of other family members were within the normal range. The homozygous missence mutation causing T→C transition at position 29170 in exon 5 of F5 gene has resulted in a Phe190Ser substitution in the proband. His younger sister was also homozygous for Phe190Ser. Heterozygosity for Phe190Ser was confirmed in his elder brother, elder sister, two daughters and niece, and their FⅤ activity were slightly decreased (57%, 73%, 72%, 66% and 75%, respectively). A normal wild type was observed in two younger brothers of the proband, and their FⅤ activity and FⅤ antigen were in the normal range.

CONCLUSIONHomozygous missence mutation of Phe190Ser has been found in above family featuring hereditary FⅤ deficiency. The homozygous missence mutation was inherited from the parents by consanguineous marriage. Phe190Ser probably underlies may underlie the pathogenesis of hereditary FⅤ deficiency in this pedigree.

Adult ; Consanguinity ; Factor V ; genetics ; Factor V Deficiency ; blood ; genetics ; Female ; Humans ; Male ; Middle Aged ; Mutation, Missense ; Partial Thromboplastin Time ; Pedigree ; Prothrombin Time ; Sequence Analysis, DNA