An abnormally decreased amount of thyroxin-binding globulin (TBG) in blood. TBG is responsible for carrying the thyroid hormones thyroxine (T4) and 3,5,3'-triiodothyronine (T3) in the bloodstream.
Comment:
Thyroxin-binding globulin is known as serpin peptidase inhibitor, clade A (alpha-1 antiproteinase, antitrypsin), member 7 (SERPINA7), Entrez Gene ID 6906. Individuals with TBG deficiency are euthyroid.