[An inherited coagulation factor VII deficiency pedigree caused by homozygous mutation of His348Gln].

Objective: To investigate the gene mutation and the molecular pathogenesis of an inherited coagulation factor VII (F VII) deficiency pedigree with consanguineous marriage.

Methods: The diagnosis was validated by coagulant parameter assay on the prothrombin time (PT), activated partial thromboplastin time, fibrinogen and coagulation factor activity. F VII gene mutations were analyzed in the proband and other family members by direct DNA sequencing of the PCR products of all exons, exon-intron boundaries and 5'and 3' untranslated sequences. The mutations were confirmed by reverse sequencing.

Results: The values of PT and F VII activity in the proband were significantly abnormal, they were 30.9 s and 3% respectively. The PT of her daughter, father and mother was slightly extended to 21.2 s, 16.3 s and 16.1 s respectively, and the F VII activity was reduced to 22%, 25% and 35% respectively. The coagulant parameters of her younger brother were within normal range. Homozygous T-->G transition at position 11482 in exon 8 was identified in the proband resulting in His348Gln, and heterozygosity for His348Gln was confirmed in her daughter and her parents, and the normal wild-type was observed in her younger brother.

Conclusion: Homozygous missense mutation of His348Gln was found in a pedigree of hereditary F VII deficiency. The mutation was inherited from her heterozygote parents.