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A two-day-old hyperthyroid neonate with thyroid hormone resistance born to a mother with well-controlled Graves'
Shuichi Yatsuga1, Yuji Hiromatsu, Shigekazu Sasaki
1Department of Pediatrics and Child Health, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, Fukuoka, 830-0011, Japan. yatsuga_shyuuichi@med.kurume-u.ac.jp.
Insights
This case report details a neonate with resistance to thyroid hormone (RTH) and hyperthyroid symptoms. Short-term treatment with methimazole and iodine proved effective and safe, suggesting a viable therapeutic option.
Area of Science:
- Endocrinology
- Genetics
- Pediatrics
Background:
- Resistance to thyroid hormone (RTH) is a rare genetic disorder.
- It is caused by mutations in the thyroid hormone receptor beta gene (TRβ).
- RTH typically follows an autosomal-dominant inheritance pattern.
Purpose of the Study:
- To report a case of RTH in a Japanese neonate.
- To describe the clinical presentation and genetic findings.
- To evaluate the efficacy and safety of short-term methimazole and iodine treatment.
Main Methods:
- A neonate presented with hyperthyroid symptoms.
- Diagnosis of RTH was made.
- Treatment with methimazole and iodine was initiated shortly after birth.
- Genetic analysis identified an R243W mutation in the TRβ gene.
Main Results:
- The neonate exhibited hyperthyroid symptoms from day two.
- Symptoms persisted for two weeks before treatment.
- Treatment with methimazole and iodine was well-tolerated with no side effects.
- The R243W mutation was identified in the patient and his father, but not his mother.
Conclusions:
- This is the first reported case of RTH in a neonate with hyperthyroid symptoms, born to a mother with Graves' disease.
- Short-term treatment with methimazole and iodine appears to be a safe and effective option for managing neonatal RTH.
- Further research is warranted to confirm these findings.
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.
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