Resistance to activated protein C as an underlying cause of recurrent venous thrombosis during relapsing nephrotic syndrome.

A 16-year-old patient with relapsing nephrotic syndrome had three episodes of deep vein thrombosis after the age of 15 years. An autosomal inherited genetic abnormality of clotting factor V, resistance to activated protein C, was found. The clinical course showed that this resistance and the nephrotic syndrome potentiated each other as risk factors for deep vein thrombosis, and long-term anticoagulation was indicated.