FAMILIAL ELEVATION OF SERUM THYROXINE-BINDING GLOBULIN CAPACITY

Abstract

ABSTRACT Elevated thyroxine-binding globulin capacity in serum (TBG) was found in five members of a family. Two males and three females in three generations had elevated TBG, protein-bound iodine and serum thyroxine but decreased dialysable thyroxine. The patients were clinically euthyroid and calculations of free thyroxine in serum and 131I uptake in the thyroid gland showed normal values. These results support the assumption that TBG is genetically controlled. The mode of transmission was consistent with dominant inheritance but it is not possible to determine whether it is x-linked or autosomal.