Genotype and phenotype analysis of congenital coagulator factor VII deficiency in four Chinese pedigrees / 中华血液学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the clinical manifestation and gene mutation in four Chinese pedigrees with the congenital coagulation factor VII deficiency.</p><p><b>METHODS</b>Prothrombin time (PT), activated partial thromboplastin time, thrombin time and plasma fibrinogen were measured using STAGO STA-R automatic coagulation analyzer, and the coagulation activity of factor VII (FVIIC) was determined by a PT-based one stage method, and factor VII antigen (FVIIAg) level by a sandwich enzyme-linked immunoabsorbsent assay. All exons, exon-intron boundaries and 3',5'untranslated regions of the FVII gene from the genomic DNA of the probands and their families were amplified by PCR, and then sequenced.</p><p><b>RESULTS</b>PT was significantly prolonged, and FVIIC and FVIIAg were decreased and the following mutations were identified in the four probands a homozygous transversion of 18041 T→G resulting in His408→Gln substitution in exon 8 in proband 1, a homozygous double nucleotide deletion, del CT (5078 - 5079) in exon 1 in proband 2, a double heterozygous of IVS6-1G→A and Gln426→stop in proband 3, and a double heterozygous of IVS6-1G→A and Arg364Gln in prohand 4.</p><p><b>CONCLUSION</b>Two missense mutations, His408Gln, Arg364Gln and one nonsense, Gln426stop in the catalytic domain of FVII and one double nucleotide deletion, del CT (5078 - 5079) in exon 1 and one splicesome mutation, IVS6-1G→A in intron 6 were separately identified in four Chinese pedigrees with inherited coagulation factor VII deficiency. The Gln426stop and IVS6-1G→A were first identified in the world and the homozygous del CT (5078 - 5079) and His408Gln were first found in China.</p>