The Neck‐thigh Radioiodine Ratio in Mongolism*

Thyroid‐stimulating Hormone and Thyroxine Levels in the Plasma of Patients With Down's Syndrome

“…Kurland, Fishman, Hamolsky and Freedberg (1957), finding an unusually rapid rate of thyroidal P" turnover with normal levels of serum protein bound iodine (PBI), suggested that the thyroid function in mongols resides in only a small portion of the gland working at an increased rate, with consequent normal total iodine uptake and level of serum protein bound iodine. Mosier (1967), who found a significantly lower one and two-hour neck/thigh ratio of I"^ in mongol than in non-mongoi subjects, also showed that, despite this defective thyroidal iodide clearance, the mongols were able to maintain normal peripheral metabolism, presumably by the intervention of some compensatory mechanism.…”