MOSIER H D
Calif Med. 1959 Jan;90(1):32-6.
Five to 10 per cent of cretinism in the United States is due to some congenital enzymatic defect in thyroid hormone synthesis. The clinical signs of hypothyroidism appear in early infancy. Differentiation from athyreotic cretinism is important because the metabolic defect tends to be familial and its presence in the patient's infant relatives should be diagnosed as early as possible. The differentiation is easily made if a goiter is discernible, but if it is not, radioiodine uptake should be measured, for in this condition the uptake is normal or greater. Thyroid replacement is the treatment in either the athyreotic state or the metabolic deficiency. The three known defects in thyroid hormone synthesis are (1) failure to oxidize iodine to elemental iodine resulting in failure of all subsequent processes; (2) failure to deiodinate free iodotyrosine, and (3) failure to form iodothyronine although the previous steps are accomplished.
在美国，5%至10%的呆小症是由甲状腺激素合成中的某些先天性酶缺陷引起的。甲状腺功能减退的临床症状在婴儿早期出现。与无甲状腺呆小症进行鉴别很重要，因为这种代谢缺陷往往具有家族性，应尽早诊断其在患者婴儿亲属中的存在情况。如果能摸到甲状腺肿大，鉴别很容易，但如果摸不到，则应测量放射性碘摄取量，因为在这种情况下摄取量正常或更高。无论是无甲状腺状态还是代谢缺陷，甲状腺替代治疗都是适用的。已知的甲状腺激素合成中的三种缺陷是：（1）碘不能氧化为元素碘，导致所有后续过程失败；（2）游离碘酪氨酸脱碘失败；（3）尽管前面的步骤已完成，但不能形成碘甲状腺原氨酸。
