Adult ; Amino Acid Substitution/genetics* ; Antithrombin III/genetics* ; Antithrombin III Deficiency/genetics* ; Asian Continental Ancestry Group/genetics* ; Base Sequence ; Binding Sites ; DNA Mutational Analysis ; Female ; Heparin/metabolism* ; Humans ; Male ; Molecular Sequence Data ; Mutation, Missense/genetics* ; Pedigree ; Republic of Korea
Abstract
We describe a case of heparin binding site Arg79Cys mutation in the gene encoding antithrombin, SERPINC1, in a Korean patient with hereditary antithrombin (AT) deficiency. The patient was a 34-year-old Korean man who presented with deep vein thrombosis (DVT) in his right leg without precipitating factors. On outpatient evaluation, coagulation tests without anticoagulation revealed a decreased AT III activity level at 48%, but normal AT III antigen level at 103%, indicating type II AT deficiency. Family studies revealed that his father (62 years of age) had decreased AT activity (48%) but had normal AT antigen levels (116%), indicating that the proband had a paternally inherited type II AT deficiency. Direct sequencing of the SERPINC1 gene in the patient and his father revealed a heterozygotic missense mutation, a cytosine to thymine substitution at nucleotide position 235 in exon 2 of the SERPINC1 gene (p.Arg79Cys). To our knowledge, this is the first report of Arg79Cys heterozygote mutation in family members with venous thromboembolism.