Clinical and genetic analysis of a pedigree affected with type I hereditary antithrombin deficiency due to a g.2736dupT variant of the AT gene

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.