RESUMO
OBJECTIVE@#To analyze the phenotype and genotype of a patient affected with inherited antithrombin deficiency.@*METHODS@#All exons and exon-intron boundaries of the AT genes were subjected to PCR amplification and Sanger sequencing. The influence of variants on the disease was predicted using bioinformatic software (MutationTaster).@*RESULTS@#The results of all coagulation tests were normal, though the antithrombin activity and antigen content of the proband and his father have decreased significantly (34%, 48% and 12.97 mg/dL, 15.60 mg/dL, respectively). His mother was normal. Genetic analysis revealed that the proband and his father both carried a heterozygous g.2736dupT variant of the AT gene. Bioinformatic analysis suggested that the variant may be pathogenic.@*CONCLUSION@#The proband and his father both had type I hereditary antithrombin deficiency caused by a g.2736dupT variant of the AT gene. The variant was unreported previously.