Factor VII deficiency is more prevalent than previously reported

The prevalence of factor (F)VII deficiency is estimated at approximately 1 of 500,000 individuals. However, low FVII activity (FVII:C) is frequently observed in a population of <500,000 in the region of Östergötland, Sweden.

To estimate the prevalence and bleeding tendency of adult FVII-deficient patients in Östergötland, Sweden.

In this retrospective cross-sectional study, the laboratory information system was used to identify adult patients with at least one FVII:C result ≤ 0.50 kilo International Units per Liter (kIU/L) between January 1, 2017, and December 31, 2022. The most likely cause was established, and in patients with a FVII deficiency, as defined by the Nordic Hemophilia Council (FVII:C < 0.35 kIU/L) or low FVII level (0.35-0.50 kIU/L), the bleeding tendency was evaluated.

FVII:C ≤ 0.50 kIU/L was identified in 97 patients residing in Östergötland. Of these, 21 had FVII deficiency, and 39 had low FVII level, corresponding to a prevalence of at least 1 of 17,800 and 1 of 9600 in the adult population in Östergötland, respectively. Patients with FVII deficiency differed significantly from patients with low FVII level in bleeding symptoms (P = .01). Of the FVII-deficient patients, 38% were asymptomatic, while 19% and 24% had experienced minor and major spontaneous bleedings, respectively.

The prevalence of FVII deficiency was estimated to be at least 1 of 17,800 adults, which is 28 times higher than the internationally claimed prevalence. Spontaneous bleeding occurred in 43% of these individuals.