High CTG repeat number in nodular thyroid tissue from a myotonic dystrophy patient.

CTG triplet expansion was studied in lymphocytes and thyroid tissue in a patient with myotonic dystrophy (DM) and associated thyroid nodular disease. An approximately 7 fold larger amplification was found in abnormal thyroid tissue compared to lymphocytes, suggesting that anomalies in the putative DM kinase gene might contribute to thyroid dysfunction.