ABSTRACT
Congenital goiter and dyshormonogenesis due to an enzymatic defect of thyroid hormone synthesis and secretion, Thyroid-stimulating hormone-ß subunit genetic abnormalities, syndromes of thyroid hormone resistance and of the thyroid hormone transport proteins, are clear examples of disorders that are caused by one or more mutations, occurring in a single gene. The role of genetic factors in the development of autoimmune thyroid disease has been inferred from clinical and epidemiological observations, such as familial clustering of Graves’ disease and Hashimoto’s chronic thyroiditis. First-degree relatives of probands have a tendency to develop autoimmune phenomena such as the appearance of autoantibodies. Autoantibodies to thyroid antigens, including thyroglobulin and thyroid peroxidase are characteristic of Graves’ disease and Hashimoto’s thyroiditis. Early studies demonstrated an increased frequency of these autoantibodies among the relatives of patients with these disorders. Autoantibodies have been found in 56% of the sibs of affected probands, and in most patients with chronic thyroiditis one or both parents were antibody-positive.
