A novel frameshift mutation leading to inherited type I antithrombin deficiency

Inherited antithrombin (AT) deficiency is an autosomal dominant thrombotic disorder. We encountered a case of inherited type I AT deficiency and identified the mutation responsible; a novel 5406delA mutation in the SERPINC1 gene appeared to have caused a frameshift with premature termination at amino acid +283. The recombinant AT protein including 5406delA was not detected in cell lysates or culture supernatants. These results will contribute to the creation of an accurate database and define the molecular basis for AT deficiency.