Factor VII deficiency in China: Phenotype, genotype and current status of management

Area of Science:

• Hematology
• Genetics
• Rare Diseases

Background:

• Congenital factor VII (FVII) deficiency presents significant clinical and molecular heterogeneity.
• Understanding the epidemiology and management of FVII deficiency in diverse populations is crucial.

Purpose of the Study:

• To investigate the clinical phenotype, F7 genotype, and current management of FVII deficiency in Chinese patients.
• To correlate FVII activity levels with bleeding symptoms and treatment outcomes.

Main Methods:

• Retrospective analysis of clinical data from 193 FVII-deficient patients in China.
• Genotype analysis of F7 gene in 55 patients.
• Assessment of bleeding symptoms, FVII activity (FVII:C), and management strategies.

Main Results:

• Epistaxis, cutaneous, and oral cavity bleeding were most common; menorrhagia affected 44.3% of reproductive-age females.
• Fatal CNS and disabling joint bleeding occurred in three patients each.
• The majority (89.6%) had FVII:C ≤10%, with significantly higher symptom rates (79.8%) compared to higher FVII:C groups.
• Major bleeds were exclusively observed in patients with FVII:C ≤10%.
• Most variants were missense (62.5%), and patients were predominantly homozygous/compound heterozygous (85.4%).
• Prothrombin complex concentrates were the primary on-demand therapy (72.4%).
• Antenatal prophylaxis reduced postpartum bleeding risk in women.

Conclusions:

• FVII deficiency in China exhibits significant bleeding symptoms, particularly in patients with FVII:C ≤10%.
• Genetic variants are predominantly missense and homozygous/compound heterozygous.
• Prothrombin complex concentrates are widely used, and antenatal prophylaxis is effective for preventing postpartum hemorrhage.