Genotypic heterogeneity may explain phenotypic variations in inherited factor VII deficiency.

Inherited factor VIl (FVII) deficiency is a rare autosomal recessive coagulation disorder characterized by a wide genet-ic heterogeneity and a poor relationship between FVII activity (FVII:C) levels and severity of the hemorrhagic diathesis. Given both the rarity and the heterogeneity of this disorder,genotype-phenotype relationships are difficult to clarify. The analysis of three FVII-deficient patients enabled us to offer some explanations.