The management of thyrotoxicosis in a pre-pubertal child with 18p deletion syndrome

Abstract

A female baby, born at term weighing 3.2 kg was noted to have bilateral ptosis and epicanthic folds. Karyotyping during infancy revealed a terminal deletion of the short arm of chromosome 18, which is known to be associated with pituitary hormone deficiency, learning difficulties, restlessness and emotional lability. At the age of 5, she was growing slowly and pituitary function testing showed satisfactory GH and cortisol responses, but TSH was below the assay threshold and free thyroxine and tri-iodothyronine were elevated. Thyrotoxicosis was confirmed and she was treated with carbimazole, which she failed to respond to, even at high doses. The drug was stopped when she became neutropenic and was rendered euthyroid with sodium iopodate prior to surgery. Total thyroidectomy was performed successfully and she has subsequently shown improvement in her cognitive symptoms and general development.