Two novel mutations in the human coagulation factor VII promoter

Area of Science:

• Genetics
• Molecular Biology
• Hematology

Background:

• Factor VII (FVII) is a crucial protein in the blood coagulation cascade.
• Genetic variations in the FVII gene can lead to bleeding disorders.
• Understanding FVII gene mutations is essential for diagnosing and managing bleeding tendencies.

Purpose of the Study:

• To identify and characterize mutations in the factor VII gene of Finnish patients with moderate bleeding tendencies.
• To investigate the functional impact of identified mutations on FVII gene expression and protein levels.
• To elucidate the molecular mechanisms underlying reduced FVII activity in affected individuals.

Main Methods:

• Screening of factor VII genes using single-strand conformational polymorphism and DNA sequencing.
• Electrophoretic mobility shift assays (EMSA) to assess nuclear protein binding affinity.
• Reporter gene assays (luciferase) to measure promoter activity.
• Southwestern blotting and UV crosslinking to identify DNA-binding proteins.

Main Results:

• Identified heterozygous mutations (A294V, -59T/G, -32A/C) and polymorphisms in FVII genes of patients.
• The -32A/C and -59T/G promoter mutations significantly reduced FVII gene promoter activity.
• Mutations altered nuclear protein binding to the FVII promoter region, affecting gene transcription.
• Plasma FVII antigen (FVII:Ag) and activity (FVII:C) levels were reduced in parallel with promoter mutations.

Conclusions:

• Novel mutations in the factor VII gene, particularly in the promoter region, are associated with moderate bleeding tendencies.
• These mutations impair FVII gene transcription by disrupting transcription factor binding, leading to reduced FVII levels and activity.
• The findings contribute to the understanding of the genetic basis of FVII deficiency and bleeding disorders.