Study of Four New Kindreds with Inherited Thyroxine-Binding Globulin Abnormalities POSSIBLE MUTATIONS OF A SINGLE GENE LOCUS

摘要

Five families with inherited thyroxine-binding globulin (TBG) abnormalities were studied. On the basis of serum thyroxine (T4)- binding capacity of TBG in affected males, three family types were identified: TBG deficiency, low TBG, and high TBG capacity. In all families evidence for X-linked inheritance was obtained and in one family all criteria establishing this mode of inheritance were met. Only females were heterozygous, exhibiting values intermediate between affected males and normals. Overlap in heterozygotes was most commonly encountered in families with low TBG.