OBJECTIVETo investigate the clinical manifestation and gene mutation in four Chinese pedigrees with the congenital coagulation factor VII deficiency.

METHODSProthrombin 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 (FVII:C) was determined by a PT-based one stage method, and factor VII antigen (FVII:Ag) 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.

RESULTSPT was significantly prolonged, and FVII:C and FVII:Ag 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.

CONCLUSIONTwo 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.