Factor VII Deficiency in China: The Genotype-Phenotype Analysis and Current Status of Management

Introduction: Congenital factor VII (FVII) deficiency is one of the rare bleeding disorders characterized by a wide molecular and clinical heterogeneity.

Aim: This study aimed to investigate the correlations among the F7 genotype, FVII activity (FVII:C) and bleeding phenotype of patients with FVII deficiency throughout China and to show their current status and management.

Methods: We retrospectively analyzed demographics, patient characteristics, clinical history and manifestation, gene mutation and treatment strategy of 193 patients with FVII deficiency registered across China.

Results: The most frequent bleeding symptoms were epistaxis (44.6%), cutaneous (38.9%), oral cavity (40.4%) bleeding and menorrhagia (44.3% of females in fertile age). Fatal central nervous system bleeding and joint deformity hemarthrosis occurred in 3 and 3 patients, respectively. The majority of patients (89.6%) belonged to the FVII:C ≤10% group and the proportion of symptomatic patients in this group (79.8%) was significantly higher than that in 10%<FVII:C≤25% (41.7%) and 25%<FVII:C≤50% group (37.5%) (Chi²=13.641, P=0.001). Major bleeds just occurred in patients with FVII:C≤10%. Most mutations were missense (62.5%) and most patients were detected with homozygous (10.9%) or compound heterozygous (74.5%) mutations. Prothrombin complex concentrates (72.4%) was the most frequently used on-demand replacement therapy. Prophylaxis before delivery could decrease the risk of postpartum bleeding in women (Chi²=69.243, P=0.000).

Conclusion: Our study provided useful information on the relationship among F7 genotype, FVII:C, clinical phenotype and current status of patient management, and may promote further exploration of FVII deficiency in the future as well as care of this population in China.

No relevant conflicts of interest to declare.