Purpose: Nonambulatory pediatric patients may have low bone mineral density (BMD) and increased risk of pathologic fractures. Though bisphosphonate therapy is the mainstream medical intervention in these children, clinical data regarding this treatment are limited. Therefore, this study aimed to evaluate the effectiveness and safety of bisphosphonate therapy in such children. Methods: We conducted a retrospective study of 21 nonambulatory children (Gross Motor Function Classification System level V) with BMD z-score ≤ -2.0 who were treated with intravenous pamidronate for at least 1 year. These patients received pamidronate every 4 months at a dose of 1.0 to 3.0 mg/kg for each cycle and had regular follow-ups for at least 1 year. The main outcome measures were changes in BMD, risk rate of fracture, biochemical data, and adverse events. Results: The average duration of pamidronate treatment was 2.0±0.9 years, and the mean cumulative dose of pamidronate according to body weight was 7.7±2.5 mg/kg/yr. After treatment, the mean lumbar spine bone mineral content, BMD, and height-for-age-z-score-adjusted BMD z-score (BMDhazZ) significantly improved. The relative risk of fracture after treatment was 0.21 (p=0.0032), suggesting that pamidronate treatment reduced fracture incidence significantly. The increase in the average dose per body weight in each cycle significantly increased the changes in BMDhazZ. Conclusion Pamidronate treatment improved the bone health of nonambulatory children with low bone density without any significant adverse events. Independent of cumulative dosage and duration of treatment, the effectiveness of pamidronate increased significantly with an increase in the average dose per body weight in subsequent cycles.

Purpose: The appropriate evaluation of height and accurate estimation of bone age are crucial for proper assessment of the growth status of a child. We developed a bone age estimation program using a deep learning algorithm and established a model to predict the final adult height of Korean children. Materials and Methods: A total of 1678 radiographs from 866 children, for which the interpretation results were consistent between two pediatric endocrinologists, were used to train and validate the deep learning model. The bone age estimation algorithm was based on the convolutional neural network of the deep learning system. The test set simulation was performed by a deep learning program and two raters using 150 radiographs and final height data for 100 adults. Results: There was a statistically significant correlation between bone age interpreted by the artificial intelligence (AI) program and the reference bone age in the test set simulation (r=0.99, p<0.001). In the test set simulation, the AI program showed a mean absolute error (MAE) of 0.59 years and a root mean squared error (RMSE) of 0.55 years, compared with reference bone age, and showed similar accuracy to that of an experienced pediatric endocrinologist (rater 1). Prediction of final adult height by the AI program showed an MAE of 4.62 cm, compared with the actual final adult height. Conclusion We developed a bone age estimation program based on a deep learning algorithm. The AI-derived program demonstrated high accuracy in estimating bone age and predicting the final adult height of Korean children and adolescents.

Purpose: Metabolic syndrome (MetS) comprises a cluster of risk factors for future cardiovascular and metabolic diseases. Only a few recent studies have reported the trend in the prevalence of MetS in youth. This study aimed to analyze trends in the prevalence of MetS and nutrient intake in the last 10 years and investigate the changes in MetS components among Korean children and adolescents. Materials and Methods: We analyzed the data of 9513 children and adolescents aged 10–19 years from the 2008–2017 Korean National Health and Nutrition Examination Surveys. Diagnosis of MetS was based on the International Diabetes Federation (IDF) and modified National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) criteria. Results: Based on the IDF criteria, MetS prevalence increased from 1.53% in 2008 to 3.19% in 2017 (p=0.007). Based on the NCEPATP III criteria, MetS prevalence increased from 2.18% in 2008 to 3.19% in 2017; however, the increase was not statistically significant. Daily calorie and fat intakes increased significantly during the study period. Among the risk factors that MetS comprises, the prevalence rates of central obesity, low high-density lipoprotein cholesterol levels, and high fasting glucose levels increased significantly. Conclusion Over the last 10 years, the prevalence of MetS has grown significantly with increasing calorie and fat intake in Korean children and adolescents. Central obesity and high-density lipoprotein cholesterol and fasting glucose levels have worsened.Therefore, active support and close monitoring are required to control MetS and prevent further increase in the prevalence of cardiovascular diseases.

X-linked adrenal hypoplasia congenita caused by a mutation in NR0B1/DAX-1 is a rare inherited disorder. Patients with adrenal hypoplasia congenita are usually diagnosed with primary adrenal insufficiency in infancy or early childhood and present hypogonadotropic hypogonadism during adolescence. Our patient first presented with adrenal crisis at the age of 2 months, which was managed with glucocorticoids and mineralocorticoids. At the age of 17 years, testicular volumes of 5 mL each and a stretched penile length of 4 cm were noted. A combined pituitary function test showed a peak luteinizing hormone level of 2.68 mIU/mL, testosterone 13.5 ng/dL, confirming hypogonadotropic hypogonadism. After whole-exome sequencing, a new variant of DAX-1, c.881T>C (p.Leu294Pro), was found. He was diagnosed with X-linked adrenal hypoplasia congenita and then treated with human choriogonadotropin for the induction of spermatogenesis as well as with steroid replacement therapy.

17α-hydroxylase/17,20-lyase deficiency, caused by mutations in the cytochrome P450 family 17 subfamily A member 1 gene (CYP17A1), is an extremely rare form of congenital adrenal hyperplasia that is characterized by diverse phenotypes resulting from specific mutations. Here, we report 2 phenotypic females with 17α-hydroxylase/17,20-lyase deficiency: one with the 46,XX karyotype presenting primary amenorrhea and sexual infantilism, and the other with the 46,XY karyotype presenting a disorder of sexual development. In both cases, the serum levels of adrenocorticotropic hormone, 11-deoxycorticosterone, and gonadotropin were elevated, whereas the levels of testosterone and dehydroepiandrosterone were reduced. Next-generation sequencing revealed one patient with compound heterozygosity for p.Trp17Ter (c.51G>A) and p.His373Leu (c.1118A>T), and the other with homozygosity for p.His373Leu (c.1118A>T). This report further describes 2 cases of 17α-hydroxylase/17,20-lyase deficiency in patients who harbored a p.His373Leu substitution, commonly found in Korean individuals, and presented diverse phenotypes.

X-linked adrenal hypoplasia congenita caused by a mutation in NR0B1/DAX-1 is a rare inherited disorder. Patients with adrenal hypoplasia congenita are usually diagnosed with primary adrenal insufficiency in infancy or early childhood and present hypogonadotropic hypogonadism during adolescence. Our patient first presented with adrenal crisis at the age of 2 months, which was managed with glucocorticoids and mineralocorticoids. At the age of 17 years, testicular volumes of 5 mL each and a stretched penile length of 4 cm were noted. A combined pituitary function test showed a peak luteinizing hormone level of 2.68 mIU/mL, testosterone 13.5 ng/dL, confirming hypogonadotropic hypogonadism. After whole-exome sequencing, a new variant of DAX-1, c.881T>C (p.Leu294Pro), was found. He was diagnosed with X-linked adrenal hypoplasia congenita and then treated with human choriogonadotropin for the induction of spermatogenesis as well as with steroid replacement therapy.

17α-hydroxylase/17,20-lyase deficiency, caused by mutations in the cytochrome P450 family 17 subfamily A member 1 gene (CYP17A1), is an extremely rare form of congenital adrenal hyperplasia that is characterized by diverse phenotypes resulting from specific mutations. Here, we report 2 phenotypic females with 17α-hydroxylase/17,20-lyase deficiency: one with the 46,XX karyotype presenting primary amenorrhea and sexual infantilism, and the other with the 46,XY karyotype presenting a disorder of sexual development. In both cases, the serum levels of adrenocorticotropic hormone, 11-deoxycorticosterone, and gonadotropin were elevated, whereas the levels of testosterone and dehydroepiandrosterone were reduced. Next-generation sequencing revealed one patient with compound heterozygosity for p.Trp17Ter (c.51G>A) and p.His373Leu (c.1118A>T), and the other with homozygosity for p.His373Leu (c.1118A>T). This report further describes 2 cases of 17α-hydroxylase/17,20-lyase deficiency in patients who harbored a p.His373Leu substitution, commonly found in Korean individuals, and presented diverse phenotypes.

Cushing syndrome (CS) is rare in children. The clinical presentation of CS varies according to extent and duration of glucocorticoid excess, and urolithiasis is a common complication. We report the first case of a patient with CS associated with acute kidney injury (AKI) due to urolithiasis. A 6-year-old boy presented to the Emergency Department with seizure. On physical examination, he had clinical features of CS and high blood pressure. Brain computed tomography (CT) suggested posterior reversible encephalopathy syndrome due to hypertension. On evaluation of hypertension, laboratory tests suggested adrenocortical tumor, but abdominal CT suggested pheochromocytoma. During further evaluation, his condition deteriorated with AKI due to bilateral ureteral stones, for which the patient underwent continuous renal replacement therapy in the intensive care unit. After controlling hypercortisolism with etomidate and performing ureteral stent indwelling, an adrenal mass was resected and histologically confirmed as an adrenocortical adenoma. We review the clinical manifestations, diagnosis, and management of CS associated with urolithiasis and AKI. Early recognition and careful monitoring of urolithiasis in CS patients are important to avoid severe complications of urolithiasis.

Hypercalcemia due to primary hyperparathyroidism (PHPT) is uncommon in children. PHPT is typically caused by a single parathyroid adenoma. Ectopic parathyroid adenomas account for 6%–16% of all parathyroid adenomas and are rare in children but should be considered in cases that present with hypercalcemia. We report the case of a 15-year-old boy with PHPT due to an intrathymic ectopic parathyroid adenoma. Neck ultrasonography and Tc-99m-sestamibi (MIBI) scanning with single-photon emission computed tomography/computed tomography (SPECT/CT) revealed ectopic parathyroid adenoma in the thymus. Video-assisted thoracoscopic surgery was performed to remove the ectopic parathyroid adenoma. Pathology showed intrathymic ectopic parathyroid adenoma. After surgery, the patient’s serum calcium level immediately normalized. Intact parathyroid hormone (iPTH) and alkaline phosphatase levels returned to normal ranges within 3 months. Delayed diagnosis of PHPT can cause end-organ damage; a timely diagnosis is especially critical to preserve bone and renal function. If ectopic parathyroid adenomas are well localized in preoperative imaging evaluation and intraoperative iPTH level decreases after resection, ectopic parathyroidectomy without bilateral neck exploration may be performed to avoid unnecessary morbidity.

Background: The incidence of type 1 diabetes mellitus (T1DM) among children is high in Europe and the USA and relatively low in Asia, including Korea. The present study aimed to investigate the incidence and prevalence of childhood-onset T1DM in Korea and examine trends in incidence. Methods: This study was conducted using the national registry data provided by the Health Insurance Review and Assessment Service in Korea from 2007 to 2017. We included children aged 0 to 14 years who were newly registered with a T1DM diagnosis each year (code E10). Results: A total of 29,013 children were registered. The overall incidence of T1DM was 4.45 per 100,000 persons (girls, 4.93; boys, 4.01). The overall incidence of childhood-onset T1DM in Korea increased from 3.70 in 2008 to 4.77 in 2016 (P=0.002). The incidence of T1DM increased from 3.07 in 2008 to 4.89 in 2016 (P<0.001) among boys. Although the incidence of the disease increased significantly among boys aged 5–9 and 10–14 years, it remained constant among girls (4.39 in 2008, 4.64 in 2016). The overall prevalence of childhood-onset T1DM in Korea increased from 32.85 in 2007 to 41.03 per 100,000 persons in 2017 (girls, 35.54 to 43.88; boys, 32.85 to 41.03). Conclusion We calculated relatively accurate incidence and prevalence of childhood-onset T1DM from a nation-based registry. The incidence increased by 3% to 4% every year from 2007 to 2017. The increasing trend is noteworthy compared with previous reports.