Detection of two novel mutations (nt2762, exon 2, CAG to TAG, and nt2483 or 2484, exon 2, +A) in individuals with congenital type I antithrombin deficiencies.

Genetic analyses were performed on two Japanese kindreds with congenital type I antithrombin deficiency causing recurrent thrombosis. The seven exons and flanking intron regions of the antithrombin gene were amplified by polymerase chain reaction followed by direct nucleotide sequencing. In case 1, one novel nonsense mutation, CAG to TAG at codon 100, nucleotide 2762, in exon 2, was detected. In case 2, one novel minor insertion, AT to AAT at codon 7, nucleotide 2483 or 2484, in exon 2, was detected, leading to a frameshift which resulted in a stop codon TGA at codon 32.