Extrahepatic portal hypertension due to familial protein S deficiency.

Portal vein thrombosis (PVT) is a common cause of portal hypertension in children. A majority of children with PVT of unknown etiology have functional Protein C deficiency or abnormally elevated levels of anti-cardiolipin antibodies. We report an 8 years old Indian girl with portal cavernoma due to hereditary Protein S deficiency. We documented familial deficiency of Protein S in 2 asymptomatic siblings suggesting that this deficiency is the primary cause of portal vein thrombosis.