Thyroid Hormone Resistance in a Preterm Infant with a Novel THRB Mutation

Resistance to thyroid hormone (RTH) is a condition caused by a mutation in the thyroid hormone receptor gene. It is rarely reported in individuals with no family history of RTH or in premature infants, and its clinical presentation varies. In our case, a premature infant with no family history of thyroid diseases had a thyroid stimulating hormone level of 85.0 µIU/mL and free thyroxine level of 1.64 ng/dL on a thyroid function test. The patient also presented with clinical signs of hypothyroidism, including difficulties in feeding and weight gain. The patient was treated with levothyroxine; however, only free thyroxine and triiodothyronine levels increased without a decrease in thyroid-stimulating hormone levels. Taken together with thyroid gland hypertrophy observed on a previous ultrasound examination, RTH was suspected and the diagnosis was eventually made based on a genetic test. A de novo mutation in the thyroid hormone receptor β gene in the infant was found that has not been previously reported. Other symptoms included tachycardia and pulmonary hypertension, but gradual improvement in the symptoms was observed after liothyronine administration. This report describes a case involving a premature infant with RTH and a de novo mutation, with no family history of thyroid disease.

Usefulness of Transient Elastography for Non-Invasive Diagnosis of Liver Fibrosis in Pediatric Non-Alcoholic Steatohepatitis

BACKGROUND: Transient elastography (FibroScan®) is a non-invasive and rapid method for assessing liver fibrosis. While the feasibility and usefulness of FibroScan® have been proven in adults, few studies have focused on pediatric populations. We aimed to determine the feasibility and usefulness of FibroScan® in Korean children. METHODS: FibroScan® examinations were performed in 106 children (age, 5–15 years) who visited the Konyang University Hospital between June and September 2018. Liver steatosis was measured in terms of the controlled attenuation parameter (CAP), while hepatic fibrosis was evaluated in terms of the liver stiffness measurement (LSM). Children were stratified into obese and non-obese controls, according to body mass index (≥ or 95% percentile) (P 5.5 kPa), whereas the remaining 29 did not (LSM < 5.5 kPa). Obese children with fibrosis had higher levels of AST (73.57 ± 56.00 vs. 39.86 ± 31.93 IU/L; P = 0.009), ALT (132.47 ± 113.88 vs. 48.66 ± 51.29 IU/L; P = 0.001), and gamma-glutamyl transferase (106.67 ± 69.31 vs. 28.80 ± 24.26 IU/L; P = 0.042) compared to obese children without fibrosis. LSM had high and significant correlation (P < 0.05) with AST, ALT, homeostasis model assessment for insulin resistance, and AST-to-platelet ratio index. CONCLUSION: FibroScan® is clinically feasible and facilitates non-invasive, rapid, reproducible, and reliable detection of hepatic steatosis and liver fibrosis in the Korean pediatric population.