: Congenital deficiency of
factor II is a very rare autosomal recessive disorder that can result in a
bleeding diathesis. Genotypically, individuals are either homozygous for a defective
prothrombin gene or a compound heterozygote with different mutated
prothrombin genes inherited from each parent. Phenotypically, it is characterized by either a low production of normal
prothrombin or a near-normal production of dysfunctional
prothrombin. Treatment is aimed at restoring normally functioning
factor II circulating levels to sufficient concentration for hemostasis. Paradoxical
thrombosis in patients born from a nonconsanguineous marriage with
factor II deficiency has not been reported. A woman with known congenital
factor II deficiency confirmed by history and
hemostatic laboratory analysis presented with an unprovoked spontaneous
thrombosis of the common femoral vein detected on color Doppler.
Venous thrombosis can occur in congenital deficiency of
factor II and
inferior vena cava filter can be life-saving.