Clinical and genotypic analysis of two Chinese pedigrees affected with hereditary coagulable factor VII deficiency / 中华医学遗传学杂志

OBJECTIVE@#To explore molecular etiology and clinical characteristics of two pedigrees affected with hereditary factor VII(FVII) deficiency.@*METHODS@#The nine exons and flanking sequences of the F7 gene of the probands were amplified by PCR. The amplicons were analyzed by direct sequencing. Suspected mutations were subjected to SWISS-MODEL modeling and analysis of protein structure change by Pymol software and conservation of amino acids across various species.@*RESULTS@#For proband of pedigree 1, the prothrombin time (PT), FVII activity (FVII:C) and FVII antigen (FVII:Ag) were 36.3 s, 3%, 53.56%, respectively. Sequencing revealed a compound heterozygous variants of c.80_81delCT and c.1371G>T(p.Arg439Ser). His son carried a heterozygous c.1371G>T (p.Arg439Ser) variant. For proband of pedigree 2, the PT, FVII:C and FVII:Ag were 22.3 s, 4%, 1.58%, respectively. Sequencing has revealed a compound heterozygous c.278G>T(p.Arg75Met) missense variant in exon 3 and c.1278T>G (p.His408Gln) in exon 9 of the F7 gene. His mother and son both carried a heterozygous c.278G>T(p.Arg75Met) variant. Three-dimensional simulation and homology analysis revealed that the p.Arg439Ser and p.Arg75Met can respectively alter part of hydrogen bonds and two highly conserved amino acids.@*CONCLUSION@#Two novel heterozygous missense variants of the F7 gene [c.1371G>T(p.Arg439Ser) and c.278G>T(p.Arg75Met)] probably account for the decrease of factor VII in the two pedigrees.

Phenotypic and genetic analysis of two pedigrees affected with hereditary coagulation FXII deficiency / 中华医学遗传学杂志

OBJECTIVE@#To carry out phenotypic and genotypic analysis for two Chinese pedigrees affected with coagulation factor XII (F XII) deficiency.@*METHODS@#Plasma prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), thrombin time (TT), and blood coagulation factor VIII, IX, XI, XII activity (FVIII:C, FIX:C, FXI:C, FXII:C) were determined with one stage clotting assay on a STAGO coagulation analyzer. FXII antigen was determined with an enzyme linked immunosorbent assay (ELISA). The 14 exons and their flanking sequences of the F12 gene were subjected to PCR amplification and Sanger sequencing. The conservation and structure of mutant protein were analyzed with MegAlign software and PYMOL software.@*RESULTS@#The APTT of the probands was significantly prolonged, while their FXII:C and FXII:Ag were significantly reduced. Genetic analysis of the proband has revealed three novel mutations in the F12 gene, including g.5972G>A splice site mutation in intron 5, g.8810_8814delGTCTA in exon 14, and g.6259G>A (p.Pro182Leu) in exon 7. In addition, a previously known mutation IVS13-1G>A has been found.@*CONCLUSION@#Four mutations have been identified in the two Chinese pedigrees, among which three were novel. Above mutations probably played a role in the defect of FXII in the two pedigrees.

Genotypic and phenotypic analysis of a case with inherited coagulation factor X deficiency / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the correlation between F10 gene mutation and its phenotype in a Chinese pedigree affected with FX deficiency.</p><p><b>METHODS</b>Prothrombin time(PT), activated partial thromboplastin time(APTT), fibrinogen, FII activity(FII:C), FVII activity(FVII:C), FIX activity (FIX:C), FX activity(FX:C) were determined with a one-stage clotting assay. The FX antigen(FX:Ag) was detected with an enzyme linked immunosorbent assay(ELISA). The 8 exons, introns and 5' and 3' untranslated regions(UTR) of the F10 gene of the proband and her family members were subjected to PCR amplification and Sanger sequencing. Suspected mutation was confirmed by reverse sequencing. Polymorphisms were excluded by direct sequencing of 100 healthy individuals.</p><p><b>RESULTS</b>The PT and APTT of the proband have prolonged to 16.1 s and 49.0 s, respectively. Her FX:C and FX:Ag were reduced by 27% and 56%, and her mother's PT, APTT, FX:C and FX:Ag were 14.8 s, 37.4 s, 44%, 34%, respectively. Her grandmother's PT, APTT, FX:C and FX:Ag were 15.8 s, 42.2 s, 31%, 45%, respectively. The results of her father and other family members were all within the normal range. Genetic analysis has revealed a heterozygous G to A mutation in the proband at position 28076 in exon 8 of the F10 gene, which resulted in a p.Gly363Ser substitution. The same mutation was also found in her mother and grandmother. No mutation of the F10 gene was found in her father. Gly363Ser may result in changes in the secondary structure of the FX protein and reduction of its activity.</p><p><b>CONCLUSION</b>The g.28076G to A(p.Gly363Ser) mutation of the F10 gene probably underlies the FX deficiency in this pedigree. The mutation was discovered for the first time in Chinese patients.</p>