Analysis of the gene mutation in an inherited FVII deficiency patient
Objective: The identify the gene defect of an inherited FVII deficiency patient.
Methods: The promoter, all the exons and exon-intron boundaries and 3' UTR of F7 gene of the proband were analyzed by direct sequencing. The defected mutations were confirmed by sequencing the complementary strand. The mutations would be screened in the related database and 150 healthy donors to identify the SNP. By splice site prediction, we analyzed the pathogenesis of defected mutations.
Results: Genetic analysis revealed G to A transition at 15975 in the intron 6 of F7 gene (IVS6-1G>A) and A to G transition at 16813 in the intron 7 of F7 gene (IVS7+7 A>G). According to the fruitfly, the acceptor site could not be recognized when a G to A substitution took place. The closest candidate splice site was located 132 bp downstream. The distance was probably too far to allow the use of the cryptic splice site and resulted in the skipping of exon6. A to G transition at 16813 in the intron 7 of F7 gene could not change the splice site, but modify a different molecular interaction that is important for the splice process.
Conclusions: The heterozygous mutation of IVS6-1G>A combined with polymorphism of IVS7+7 A>G in F7 gene relates to the FVII deficiency.