Severe Factor VII Deficiency Due to a Mutation Disrupting an Sp1 Binding Site in the Factor VII Promoter

Abstract

We have identified a point mutation in the promoter of the factor VII gene responsible for a severe bleeding disorder in a patient from a large French-Canadian family with known consanguinity. The proband has an extremely low plasma level of factor VII antigen and factor VII coagulant activity (<1 percent of normal) and suffers from hemarthroses and chronic arthropathy. Sequencing of the patient’s factor VII 5′ flanking region, intron/exon junctions, and coding regions showed a homozygous point mutation, a C to G transversion at position −94 relative to the translation start site. We show here that this mutation prevented binding of transcription factor Sp1 and of other nuclear proteins to this region of the factor VII promoter and resulted in a 20-fold reduction in reporter gene expression in HepG2 cells. These data underscore the importance of this region of the factor VII promoter for in vivo expression of the factor VII gene.© 1998 by The American Society of Hematology.

Factor VIIa replacement therapy in factor VII deficiency

“…While the incidence of FVII deficiency in the general population is approximately one in 500 000, in the French‐Canadian population of the small village where it was studied, the incidence is approximately one in 335 [11]. A mutation of a C to G transversion at position −94 within the core binding site of transcription factor Sp1 was identified as the mutation most commonly responsible for FVII deficiency in this population [12].…”

“…(iii) In vitro replacement of recombinant factor VIIa : Three CRM– FVII‐deficient individuals (subjects 1–3) were selected from the French‐Canadian descendent pool of FVII‐deficient individuals [11,12]. Sequencing the subjects FVII promoter region, confirmed that these individuals were homozygous for the −94 C to G transversion.…”

Molecular Biology and Clinical Manifestation of Hereditary Factor VII Deficiency

“…The found new DNA polymorphisms in the promoter region (Ϫ122T>C) and in intron 1a (73G>A) were detected by sequencing or restriction analysis by BmyI and MspI, respectively. 6,7…”

“…2,4,5 FVII activity is influenced not only by mutations of the factor VII gene but also by allelic polymorphic variations of the gene. Eight polymorphisms within FVII gene are known, 6,7 three of which influence the level of FVII activities: an insertion polymorphism of the promotor, 8 a repeat polymorphism within intron 7, [9][10][11][12] and the Arg353 Gln polymorphism of exon 8. 13 The hemorrhagic diathesis in patients with FVII deficiency can be highly variable and does not necessarily correlate with the level of FVII activities.…”

Factor VII Gene Defects: Review of Functional Studies and Their Clinical Implications

“…Low mRNA expression ELISA/CA/qRT-PCR [73] SPCD Arg277Cys LP Low secretion/ moderate activity ELISA/CA/qRT-PCR [73] SPCD Arg353Gln Benign None ELISA/CA/qRT-PCR [73] Gla domain Ser23Pro PA LTB Crystallography/CA [54] EGF-like-2 domain Cys135Arg PA Disrupted disulfide bond Crystallography/CA [54,74] SPCD Arg247Cys PA LTB Crystallography/CA [54] SPCD Ser282Arg PA LTB Crystallography/CA [54] SPCD Ser363Ile PA LTB Crystallography/CA [54] SPCD Trp364Cys PA LTB Crystallography/CA [54] SPCD Trp364Phe PA LTB Crystallography/CA [54] SPCD Pro303Thr PA LTB Crystallography/CA/ELISA/ solid-phase binding assay [54,60] Gla domain Phe24del PA LTB Crystallography/CA [56] EGF-like-2 domain Arg110Cys PA IPF Clotting assay/EIA [18] EGF-like-2 domain Asp123Tyr PA IPF Clotting assay/EIA [18] Promoter -94C>G PA Low Sp1 binding Reporter gene expression assay/ electrophoretic mobility shift assay [75] SPCD, serine protease catalytic domain; PA, pathogenic; LP, likely pathogenic; LS, low secretion; LCA, low coagulative activity; LTB, low TF binding; IPF, impaired protein folding; HE, high expression; LE, low expression; CM, confocal microscopy; FM, fluorescence microscopy; CA, coagulation assay; Ref. reference of FVIIa is not well known, previous studies have indicated that different F7 gene variations can change this interaction and decrease the coagulation activity of the protein [54] .…”