Familial and sporadic thyroglobulin deficiency with goitre and hypothyroidism

The thyroid proteins and iodocompounds were analysed in the thyroid tissue of 4 patients with nontoxic goitre. Subtotal thyroidectomy was performed for tracheal compression. The thyroid components were labelled with a trace amount of 125I before operation. One patient had congenital goitre and hypothyroidism with cretinoid features. Three other patients belonged to the same family. Two had congenital goitre, one of them with subclinical and biochemical hypothyroidism. There was a range of thyroglobulin (TG) deficiency ranging from virtual absence of TG in the most affected patient to 17% of normal in the least affected one. There seemed to be an inverse relationship between TG content and clinical signs. Also with decreasing TG more iodocompounds were found in the 3-8 S region on gradient centrifugation. In the most affected patient all the radioactivity was in the 3-8 S region, in the least affected one it was all found in the 19 S and 27 S regions. The other patients had an intermediate pattern. The 3-8 S fraction contained albumin, IgG and some material which reacted like TG on immunoelectrophoresis except for the least affected patient. The iodine content was normal whereas the iodination of TG was low-normal or low. Iodotyrosines and iodothyronines were found in all glands analysed on column chromatography but only in the most heavily affected patient did the ratio iodotyrosines/iodothyronines seem to be elevated. Evidently TG was not necessary for hormone formation in this gland but the efficiency of the matrix seemed not to suffice for normal hormone production.