No mutations in the translated region of exon 1 in the TSH receptor in Graves' thyroid glands.

We have amplified a 285 base pair by nested polymerase chain reaction 38 nucleotide downstream from the most 5' transcription initiation site (7) encoding 55 of the 57 residues of exon 1 of the human TSH receptor. These DNA were amplified from 10 tissue blocks of thyroid tissue removed at subtotal thyroidectomy from 10 patients with Graves' disease. The amplified 285 nucleotide fragments were sequenced in search of mutations in the coding region of exon 1 and polymorphism in the 120 nucleotides of the untranslated region upstream of the first ATG codon. No such variations were found. We conclude that the polymorphism or mutation of the part of the TSH receptor extracellular domain encoded by exon 1 and of sequences immediately upstream of the first ATG codon are not relevant to the pathogenesis of Graves' disease.