Inherited disorders of thyroid metabolism.

In summary, we have presented a brief survey of the current state of knowledge of inherited disorders of thyroid metabolism. Analysis of cases shows that the biochemical classification covers a wide range of abnormalities and it is likely that further biochemical studies will increase this heterogeneity as well as refining it. Genetic studies are often incomplete, and few in number compared with the classical study by Hutchison and McGirr of Scottish tinker families. Most important, this survey indicates that further research is needed to elucidate the precise molecular mechanisms of the working of the iodide pump, the oxidation and iodination and coupling mechanisms. Study of animal models and DNA sequencing and hybridization work will continue to expand our understanding of abnormalities of thyroglobulin metabolism. We urgently need to find the key to resistance of peripheral and pituitary tissues to thyroid hormone. Subtle dyshormonogenetic abnormalities may await discovery in the field of multinodular goiter and intrathyroidal calcification with goiter. Neonatal screening for hypothyroidism is likely to expand the number of cases for investigation and detailed study. There is an important relationship of dyshormonogenesis to follicular carcinoma. It is hoped that in time we will be able to transform inborn errors into areas of understanding in the realm of the thyroid gland.