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