Case report
A two-day-old hyperthyroid neonate with thyroid hormone resistance born to a mother with well-controlled Graves’ disease: a case report
1 Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, Fukuoka, 830-0011, Japan
2 Department of Medicine, Division of Endocrinology and Metabolism, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, Fukuoka, 830-0011, Japan
3 Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka, 431-3192, Japan
Journal of Medical Case Reports 2012, 6:246 doi:10.1186/1752-1947-6-246
Published: 20 August 2012Abstract
Introduction
Resistance to thyroid hormone is a syndrome caused by thyroid hormone receptor β mutations, which are usually inherited in an autosomal-dominant pattern.
Case presentation
Our patient, a Japanese neonate boy, showed hyperthyroid symptoms at age two days. Although our patient was diagnosed as having resistance to thyroid hormone, his hyperthyroid symptoms continued for two weeks. Therefore, our patient was treated with methimazole and iodine for two weeks from birth, showing no side effects and no symptoms upon treatment. At age 70 days, an R243W mutation in thyroid hormone receptor β was detected in our patient; while absent in his mother, the mutation was present in his father, who never showed any symptoms.
Conclusions
To the best of our knowledge this is the first case report of a resistance to thyroid hormone in a neonate presenting with hyperthyroid symptoms born to a mother with Graves’ disease and treated with methimazole and iodine. These results suggest that methimazole and iodine may be a good short-term option for treatment.



