A Case of Pediatric Unprovoked Deep Vein Thrombosis due to Combined Hereditary Thrombophilia of Antithrombin III and Protein S Deficiency / 임상소아혈액종양

ABSTRACT

Unprovoked deep vein thrombosis (DVT) is uncommon in pediatric patients and, among those, combined hereditary thrombophilia is particularly rare. We present a 9-year-old Korean boy who developed lower extremity pain with swelling, and was diagnosed with unprovoked DVT due to hereditary (combined hereditary thrombophilia). Coagulation test revealed antithrombin III and protein S deficiency. The genetic work up confirmed the first case of combined antithrombin III deficiency and protein S deficiency by SERPINC1 heterozygous termination mutation [c.685C>T (p.Arg229*)] and PROS1 heterozygous missense mutation [c.1597G>A (p.Val533Met)]. He was treated with continuous heparin and catheter intervention but those were ineffective or transiently effective. His DVT gradually improved only after prolonged anticoagulation.