Genomic DNA analysis of thyrotropin receptor in a family with hereditary hyperthyroidism

Mutations of the thyrotropin receptor (TSH-R) gene have been reported in so me cases of hyperthyroidism. We report a case of a family that had a high i ncidence of hyperthyroidism (6/13) which strongly suggested hereditary fact ors. We then analyzed whether the family had mutations of the TSH-R gene. N o significant mutations in exon 10 of the TSH-R gene were found in the pati ent by restriction fragment length polymorphism analysis and polymerase cha in reaction direct sequencing, when compared with those with 4 normal subje cts and 2 patients with Graves' disease. Unknown mutations in the extracell ular region of the receptor or other genes in this family remain to be stud ied.