Safe childbirth for a type 1 antithrombin-deficient woman with novel mutation in the SERPINC1 gene undergoing antithrombin concentrate therapy.

: Inherited antithrombin (AT) deficiency is an autosomal dominant thrombotic disorder. We encountered a case of inherited type I AT deficiency and identified the causative mutation; a novel c.7430A>G missense mutation in the SERPINC1 gene in which tyrosine was substituted for cysteine at the 292nd amino acid. A recombinant AT protein with the 7430A>G mutation was not detected in cell lysates or culture supernatants. And then, our patient without personal or family history of thrombosis was pregnant woman with asymptomatic AT deficiency. Our patient treated with only AT concentrate therapy during pregnancy and she was able to safely give birth naturally and avoid thrombosis. We believe that this therapy for pregnant woman with asymptomatic AT deficiency is effective and safety as anticoagulant therapy during pregnancy.