An eight day old hyperthyroid neonate with a resistance to thyroid hormone

Abstract

A tunisian newborn girl presented for a systemic clinical control at the age of eight days with tachycardia. Biochemical findings showed high levels of FT4 and TSH. Molecular analysis of the β-receptor for thyroid hormones gene demonstrated the A268D mutation in exon 8 in the heterozygous state responsible for resistance to thyroid hormones. Her parents and her brother showed no mutation. Betablocker treatment was inefficient on the tachycardia so it was discontinued after one month. During 5 years of follow-up, she had normal mental development, tachycardia disappeared, had recurrent media otitis.