Neonatal arterial iliac thrombosis in type-I protein C deficiency: a case report

A male infant born by caesarean section at 38 weeks of gestational age (B.W. 4055 g; Apgar 9-10), in the first two hours of life his right leg became hypovascularizated. Normal values of leukocities, red cells, haematocrit, hemoglobin, platelets. C-Reactive Protein negative. Electrolytes and coagulation tests were normal. Normal vitamin K coagulation proteins levels. Serological tests for TORCH (IgM) and Parvovirus (IgG and IgM) were negative. Sonography showed a reduced blood flow in the iliac artery and reported a 1 cm long vessel thrombosis. From 8 hours of life we administred an intravenous infusion of unfractionated heparin (UFH) 75 UI/Kg for the first 10 minutes then 28 UI/Kg/h. On the 2nd day tests were performed to assess absence of inhibiting-clot factors. The dosage of homocysteine, protein S and antithrombin was normal. FV Leiden and antiphospholipid antibodies were negative. The mapping of G20210A prothrombin's gene resulted normal, whereas the concentration of Protein C was lower than normal: activity 46% (68-150%), antigen 35% (70-150%). The same deficiency was also found in the father. The mother showed normal concentrations. No episodies of thrombosis events were documentated in the family. The intravenous unfractionated heparin (UFH) therapy was replaced after 64 hours by subcutaneous nadroparin 600 UI twice/day, which was stopped 5 days later when the vessel sonografic images were completely normal. During the hospitalization the infant didn't show bleeding. The child was followed-up yearly until 4 years of age: he was well and had a normal body and mental development. The final diagnosis is likely to be of a permanent protein C deficiency in heterozygous form. Our case is interesting because the first manifestation was an important thrombosis of large vessel that occurred within a few hours of life in absence of perinatal risk factors, as if it was a homozygous disease, but the patient had a heterozygotic form. In literature few cases are reported of heterozygous forms that became symptomatic, but only in old age. After a severe first manifestation, a normal and asymptomatic development is uncommon without new thrombotic episodes. In our patient the neonatal thrombosis was the sole event in his life.