[Neonatal renal vein thrombosis in a heterozygous carrier of both factor V Leiden and prothrombin mutations].

Unlabelled: We report a case of renal vein thrombosis, treated with heparin and thrombolytic therapy, in a patient who was heterozygous for both factor V Leiden and prothrombin mutations.

Case Report: A full-term infant was treated with heparin and fibrinolytics at the fourth day of life because of renal vein thrombosis, inferior vena cava thrombosis and adrenal hemorrhage. After four days of treatment, the repermeabilization was complete but a renal atrophy developed. The investigation for congenital coagulation disorders revealed a heterozygous mutation for both factor V Leiden and prothrombin.

Conclusion: Search for inborn blood coagulation disorders should be systematic in the newborn infant with venous thrombosis because of the risk of recurrence, even in the presence of a known acquired risk factor. The thrombolytic treatment improves the prognosis.