Isolated Lack of Thyrotropin in Man

Abstract

A patient with an isolated lack of thyrotropin, confirmed by measurement of plasma thyrotropin, is presented. Gonadotropin, corticotropin and growth hormone were presented although the hormone response to hypo-glycemia was blunted. This patient appears to be the first in whom plasma growth hormone was demonstrated in the absence of plasma thyrotropin. The diagnosis of deficiency of thyrotropin in general as well as in the particular case of an isolated deficiency is discussed. Measurement of plasma thyrotropin may be necessary although it was not required to establish the diagnosis in our patient. Although probably not common, the isolated deficiency might be suspected in any patient with hypothyroidism.