A 2-month-old infant girl with a history of persistent physiological jaundice following birth is now reported by her parents to sleep excessively and display little activity. Physical examination reveals abnormal deep tendon reflexes, hypothermia, and muscular hypotonia. Based on this information, which of the following would be the best therapy for her condition?

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Quizplus · Accepted Answer

The symptoms described, including persistent jaundice, lethargy, abnormal reflexes, hypothermia, and hypotonia, are indicative of congenital hypothyroidism. The best therapy for this condition is thyroxine (levothyroxine) replacement.  This infant has cretinism, a condition caused by a neonatal lack of thyroxine. Thyroid agenesis, iodine deficiency, ingestion of goitrogens, and hereditary enzymatic deficiencies may all result in a relative lack of biologically active thyroxine. Affected children may display lethargy, jaundice, hypothermia, muscular hypotonia, and mental retardation. Medicinal replacement of thyroxine is therapeutic. The mental retardation may not be reversible, however, unless treated early.

A 2-Month-Old Infant Girl with a History of Persistent Physiological