Hereditary abnormalities of thyroxine-binding globulin concentration. A study of 19 kindreds with inherited increase or decrease of thyroxine-binding globulin.

Nineteen families with hereditary abnormalities of thyroxine-binding globulin (TBG) have been studied, comprising a total of 15 males with absent TBG, and 15 females heterozygotic for this condition, and 14 males with excess of TBG and 44 heterozygotic females. Hereditary TBG excess was associated with thyrotoxicosis in four instances, and with myxoedema in three. The typical biochemical features of TBG abnormality are described, with the clinical histories of patients in whom diagnostic and management problems occurred.