2022 Clinical practice guidelines for central precocious puberty of Korean children and adolescents.

The Committee of Central Precocious Puberty of Korean Pediatrics and Adolescents of the Korean Society of Pediatric Endocrinology has newly developed evidence-based 2022 clinical practice guidelines for central precocious puberty in Korean children and adolescents. These guidelines provide the grade of recommendations, which includes both the strength of recommendations and the level of evidence. In the absence of sufficient evidence, recommendations are based on expert opinion. These guidelines have been revised and supplement the previous guidelines "Clinical Guidelines for Precocious Puberty 2011," and are drawn from a comprehensive review of the latest domestic and international research and the grade of recommendation appropriate to the domestic situation. This review summarizes the newly revised guidelines into 8 key questions and 27 recommendations and consists of 4 sections: screening, diagnosis, treatment, and long-term outcome of central precocious puberty.

Evaluation of users' level of satisfaction for an artificial intelligence-based diagnostic program in pediatric rare genetic diseases.

The artificial intelligence (AI)-based genetic diagnostic program has been applied to genome sequencing to facilitate the diagnostic process. The objective of the current study was to evaluate the experience and level of satisfaction of participants using an AI-based diagnostic program for rare pediatric genetic diseases. The patients with neurodevelopmental disorders or hearing impairments, their guardians, and their physicians from 16 tertiary general hospitals were enrolled. The study period was from April 2020 to March 2021. A survey was designed to assess their experience and level of satisfaction. A total of 30 physicians and 243 patients and guardians (199 neurodevelopmental disorders and 44 hearing impairments) completed the survey. DNA samples of the subjects were collected through buccal swabs or blood collection: 211 subjects (86.8%) through buccal swab and 29 subjects (11.9%) through blood collection. Average turnaround time for result receipt was 57.54 ± 32.42 days. For the sampling method, 193 patients and guardians (81.1%) and 28 physicians (93.3%) preferred buccal swab. The level of satisfaction of the 2 groups participating in the AI-based diagnostic program was 8.31 ± 1.71 out of 10 in the patient and guardian group and 8.42 ± 1.23 in the physician group. Clinicians, patients, and guardians are satisfied with the AI-based diagnostic program in general. With an increase in AI-based precision medicine solutions, the evaluation of the user's satisfaction with appropriate provision will help improve personal health care.

Comparison of Initial Presentation of Pediatric Diabetes Before and During the Coronavirus Disease 2019 Pandemic Era.

BACKGROUND: Hospital visitation has become challenging during the coronavirus disease 2019 pandemic because of quarantine measures and fear of infection. Consequently, newly diagnosed patients may present with more severe diseases during the pandemic. The present study analyzed the differences in the initial clinical presentations of newly diagnosed patients with type 1 diabetes (T1D) and type 2 diabetes (T2D), comparing pre-pandemic and pandemic periods. METHODS: Newly diagnosed patients with T1D or T2D and aged < 18 years during 2018-2020 were included in the study. Data were collected retrospectively from four academic centers in Gyeonggi-do, South Korea. Initial clinical data were compared between the pre-pandemic (2018-2019) and pandemic (2020) periods. RESULTS: In the pre-pandemic and pandemic periods, 99 patients (41 T1D and 58 T2D patients) and 84 patients (51 T1D and 33 T2D patients) were identified, respectively. During the pandemic, the proportion of diabetic ketoacidosis (DKA) cases increased compared to the pre-pandemic period (21.2% during 2018-2019 vs. 38.1% in 2020; P = 0.012). In the pre-pandemic and pandemic periods, initial pH was 7.32 ± 0.14 and 7.27 ± 0.15, respectively (P = 0.040), and HbA1c values were 11.18 ± 2.46% and 12.42 ± 2.87%, respectively (P = 0.002). During the pandemic, there was an increased risk of DKA in patients with T1D (odds ratio, 2.42; 95% confidence interval, 1.04-5.62; P = 0.040). CONCLUSION: During the pandemic, the proportion of DKA in newly diagnosed patients with T1D increased and clinical parameters showed a deteriorating pattern. Increased awareness of pediatric diabetes, especially DKA, could facilitate visit to the hospital for an early diagnosis; thus, reducing the number of DKA cases during the pandemic era.

Diagnostic performance of automated, streamlined, daily updated exome analysis in patients with neurodevelopmental delay.

BACKGROUND: The diagnostic yield of whole-exome sequencing (WES) varies from 30%-50% among patients with mild to severe neurodevelopmental delay (NDD)/intellectual disability (ID). Routine retrospective reanalysis of undiagnosed patients has increased the total diagnostic yield by 10-15%. Here, we performed proband-only WES of 1065 patients with NDD/ID and applied a prospective, daily reanalysis automated pipeline to patients without clinically significant variants to facilitate diagnoses. METHODS: The study included 1065 consecutive patients from 1056 nonconsanguineous unrelated families from 10 multimedical centers in South Korea between April 2018 and August 2021. WES data were analyzed daily using automatically updated databases with variant classification and symptom similarity scoring systems. RESULTS: At the initial analysis, 402 patients from 1056 unrelated families (38.0%, 402/1,056 families) had a positive genetic diagnosis. Daily prospective, automated reanalysis resulted in the identification of 34 additional diagnostic variants in 31 patients (3%), which increased our molecular diagnostic yield to 41% (433/1056 families). Among these 31 patients, 26 were diagnosed with 23 different diseases that were newly discovered after 2019. The time interval between the first analysis and the molecular diagnosis by reanalysis was 1.2 ± 0.9 years, which was shorter in the patients enrolled during the latter part of the study period. CONCLUSION: Daily updated databases and reanalysis systems enhance the diagnostic performance in patients with NDD/ID, contributing to the rapid diagnosis of undiagnosed patients by applying the latest molecular genetic information.

Association between Dietary Habits and Parental Health with Obesity among Children with Precocious Puberty.

Precocious puberty, resulting in various physical, mental, and social changes, may have negative consequences for children and their families. In this study, we investigated whether there were differences between parental obesity, children's and parent's awareness of body shape, and dietary habits according to obesity levels in children with precocious puberty. A total of 193 children (93.3% girls) diagnosed with precocious puberty were classified into three groups according to their obesity levels. Negative body shape awareness and dissatisfaction were significantly higher in the obese group than in the normal-weight group, and parents were more likely to perceive their children as fat than the children themselves. In addition, the obesity rate of parents in the obese group was higher, and the body mass indexes of children and parents were significantly correlated. The nutrition quotients (NQs) were revealed to be significantly lower in the obese group with significantly lower scores. The significant factors related to obesity were the awareness of a fatty body image and dissatisfaction, obesity of the parents, and the NQ. The results show that obese children with precocious puberty were more vulnerable to negative lifestyle, family environment, and self-esteem effects than their normal-weight peers. Therefore, various interventions, such as environmental management, psychological support, and nutrition education, are needed that focus on the obesity and health conditions of children with precocious puberty.

Rare Cases of PLOD1-Related Kyphoscoliotic Ehlers-Danlos Syndrome in a Korean Family Identified by Next Generation Sequencing.

Kyphoscoliotic Ehlers-Danlos syndrome (kEDS) is an autosomal recessive connective tissue disorder characterized by muscular hypotonia, hyperextensible skin, skin fragility, joint hypermobility, and progressive kyphoscoliosis. The disorder results from a deficiency of the enzyme collagen lysyl hydroxylase 1 due to mutations in the gene PLOD1. We describe the rare cases of kEDS in Korean siblings with two novel compound heterozygous variants, c.926_934del (p.Leu309_Leu311del) and c.2170_2172del (p.Phe724del) in the PLOD1 gene. They had congenital hypotonia, joint laxity, skin hyperextensibility, Marfanoid habitus, high myopia and atrophic scarring. The younger sibling had an early-onset progressive kyphoscoliosis, while the older sibling showed mild scoliosis during childhood. Intrafamilial variability of the clinical severity and age of kyphoscoliosis onset observed in our cases.

Frequency of Self-Monitoring of Blood Glucose during the School Day Is Associated with the Optimal Glycemic Control among Korean Adolescents with Type 1 Diabetes.

BACKGROUND: This study aimed to evaluate the relationship between the frequency of self-monitoring of blood glucose (SMBG) and glycosylated hemoglobin (HbA1c) levels among Korean adolescents with type 1 diabetes mellitus (T1DM). Factors affecting the SMBG frequency were analyzed in order to improve their glycemic control. METHODS: Sixty-one adolescents aged 13 to 18 years with T1DM were included from one tertiary center. Clinical and biochemical variables were recorded. Factors associated with SMBG frequency were assessed using structured self-reported questionnaires. RESULTS: Average total daily SMBG frequency was 3.8±2.1 and frequency during the school day was 1.3±1.2. The mean HbA1c level was 8.6%±1.4%. As the daily SMBG frequency increased, HbA1c levels declined (P=0.001). The adjusted odds of achieving the target HbA1c in participants who performed daily SMBG ≥5 significantly increased 9.87 folds (95% confidence interval [CI], 1.58 to 61.70) compared with those performed SMBG four times a day. In the subjects whose SMBG frequency <1/day during the school day, an 80% reduction in the adjusted odds ratio 0.2 (95% CI, 0.05 to 0.86) showed compared to the group with performing two SMBG measurements in the school setting. The number of SMBG testing performed at school was significantly high for individuals assisted by their friends (P=0.031) and for those who did SMBG in the classrooms (P=0.039). CONCLUSION: Higher SMBG frequency was significantly associated with lower HbA1c in Korean adolescents with T1DM. It would be necessary to establish the school environments that can facilitate adequate glycemic control, including frequent SMBG.

Measles outbreaks in the Kyeongin area of the Republic of Korea, 2013-2014: A single-center experience in a country of measles elimination.

OBJECTIVE: To identify the source of infection and determine the clinical features and laboratory finding of measles infection. METHODS: In 27 measles patients, except for 3 adult patients, the rest of 24 pediatric measles cases were analyzed with regard to age, sex, immunization status, transmission routes and molecular genotyping of measles virus. Eighteen measles patients who admitted in isolation ward were set apart to investigate clinical findings and its correlation with laboratory characteristics. Retrospective analysis of cases was conducted in this study. RESULTS: Of the 24 pediatric patients, 23 (95.8%) had not received any measles-containing vaccine (MCV). Sixteen of the patients (66.7%) were aged <12 months. The suspicious index case of a girl aged 34 months was not vaccinated with MCV1 and got measles after a trip to Philippines, and molecular genotype was revealed as B3. Measles outbreaks in the community such as a restaurant were followed by this one imported case. According to analysis of 18 patients admitted in isolation ward, the median level of C-reactive protein (CRP) was 0.38 mg/dL and that of lactate dehydrogenase (LDH) was 1200 IU/L. All of the 18 patients had LDH levels above the normal range. Age correlated with CRP (ρ = 0.528, P = 0.024) and LDH (ρ = 0.501, P = 0.034). The duration of fever was correlated with the duration of fever before rash (ρ = 0.898, P < 0.01). The duration of hospitalization was correlated with CRP (ρ = 0.586, P = 0.011). The white blood cell counts were correlated with the levels of LDH (ρ = 0.505, P = 0.033), aspartate aminotransferase (ρ = 0.507, P = 0.032), and alanine aminotransferase (ρ = 0.481, P = 0.043). CONCLUSIONS: Early weaning of maternally derived measles antibodies therefore vaccination of MCV1 at a young age from 9 months to 12 months should be considered in situations of early exposure. Furthermore, there is a call for consideration of scheduling an earlier age for the first dose of MMR vaccine in Europe. It is necessary for Korea to investigate the duration of the presence and quantitative analysis of maternal measles antibodies in infants and to reconsider the timing of MCV1.

An update on the genetic causes of central precocious puberty.

Central precocious puberty (CPP) is caused by the premature reactivation of the hypothalamic-pituitary-gonadal axis. Genetic, nutritional, and environmental factors play a crucial role in determining pubertal timing. Recently mutations in kisspeptin (KISS1), kisspeptin receptor (KISS1R), and makorin RING finger protein 3 (MKRN3) genes have been identified as genetic causes of CPP. In particular, the MKRN3 gene is known to affect pubertal initiation. The MKRN3 gene is located on chromosome 15q11-q13 in the Prader-Willi syndrome (PWS) critical region. MKRN3 deficiency, due to a loss of function mutation, leads to the withdrawal of hypothalamic inhibition and prompts pulsatile gonadotropin-releasing hormone secretion, resulting in precocious puberty. The exact functions of these genes associated with CPP are still not well understood. Larger studies are required to discover the mechanisms involved in pubertal development.

Diverse genetic aetiologies and clinical outcomes of paediatric hypoparathyroidism.

CONTEXT: Hypoparathyroidism is characterized by hypocalcaemia, hyperphosphataemia, and low or inappropriately normal parathyroid hormone (PTH) levels. Idiopathic or genetic drivers are the predominant causes of hypoparathyroidism in paediatric-age patients. OBJECTIVE: This study investigated the aetiology and clinical course of primary hypoparathyroidism in infancy and childhood. SUBJECTS AND MEASUREMENTS: This study included 37 patients (23 males, 14 females) with primary hypoparathyroidism diagnosed prior to 18 years of age. We analysed aetiologies, initial presentation, age at diagnosis, endocrine and radiological findings, and outcomes. RESULTS: The median age at presentation was 1·7 months (range 1 day-17 years), and the mean follow-up duration was 7·0 ± 5·3 years (range 0·5-16·8 years). Our cohort included 22 cases (59·5%) of 22q11·2 microdeletion syndrome. Other aetiologies included hypoparathyroidism-deafness-renal dysplasia syndrome (5/37, 13·5%) and one patient each with autoimmune polyglandular syndrome type 1, Kearns-Sayre syndrome and Kenny-Caffey syndrome. The remaining 7 (18·9%) patients were classified as idiopathic hypoparathyroidism cases. Among the 15 patients who underwent brain imaging, 5 (33·3%) had basal ganglia calcification. Among the 26 patients examined by renal imaging, 5 (19·2%) had either nephrocalcinosis or a renal stone. After 11 months of calcium or calcitriol supplementation, 16 patients (43·2%) discontinued medication. The final PTH levels were significantly higher in patients with transient hypoparathyroidism than those with permanent hypoparathyroidism. CONCLUSIONS: Identification of the genetic aetiologies of hypoparathyroidism makes it possible to predict patient outcomes and provide appropriate genetic counselling. Long-term treatment with calcium and calcitriol necessitates monitoring for renal complications.

Turner syndrome masquerading as normal early puberty.

Approximately 50% of patients with Turner syndrome (TS) have complete loss of one X chromosome, whereas the rest of the patients with TS display mosaicism or structural abnormalities of the X chromosome. Most well-known common features are short stature and gonadal failure. Approximately one third of girls with TS may enter spontaneous puberty, but only half those completed with menarche. However, some atypical features of TS have been described. Many studies have been conducted to verify and delineate proposed loci for genes pertaining to the TS phenotype, and correlations between karyotype and phenotype. A few rare cases of precocious puberty with TS have been described. Here we describe a case of TS with the Xp22.1 deletion presenting with short final stature, early normal onset of spontaneous puberty, and Graves' disease, without short stature during puberty.

Predictive factors for organic central precocious puberty and utility of simplified gonadotropin-releasing hormone tests.

BACKGROUND: The aim of the present study was to determine whether the clinical presentation of patients with central precocious puberty (CPP) permits differentiation between idiopathic and organic forms, and to examine whether luteinizing hormone (LH) determination in single blood sample after gonadotropin-releasing hormone (GnRH) administration is sufficient to diagnose CPP. METHODS: Potential clinical and laboratory predictors for the presence of central nervous system (CNS) abnormalities were assessed. Sensitivities and specificities of LH and follicle-stimulating hormone (FSH) levels at 0, 15, 30, 60, 90 and 120 min were compared after GnRH stimulation. RESULTS: In 45 girls with signs of breast development, 26 were diagnosed as having CPP. The age of onset in patients with organic CPP was 4.75 +/- 2.01 years (range 1.2-7.1 years, median 5.0 years), whereas the age in patients with idiopathic CPP was 7.09 +/- 0.87 years (range 5.0-7.9 years, median 7.0 years). This parameter is the only one showing statistical significance. In addition, the specimen at 30 min after GnRH stimulation yielded highest sensitivity for the diagnosis of CPP. CONCLUSIONS: The earlier the onset of disease, the higher the possibility of presence of CNS lesion. According to the mean GnRH-stimulated LH levels and sensitivity at each time, a single blood sample obtained for LH determined after GnRH administration at 30 min can be used to diagnose CPP.

Short-term efficacy of monthly pamidronate infusion in patients with osteogenesis imperfecta.

We evaluated the efficacy of a monthly infusion of pamidronate on the frequency of fractures, biochemical effects, and bone mineral density in children with osteogenesis imperfecta. Eleven patients from 0.9 to 13.8 yr of age were included in this study. The patients were administered pamidronate intravenously (30 mg/m(2)) over a 4-hr period monthly for a period ranging from 6 to 37 months. Height and weight Z-scores did not change significantly. The frequency of fractures was decreased from 2.3+/-1.01 times per year before treatment to 0.6+/-0.69 times per year during treatment. There were no long-term changes in biochemical markers during pamidronate therapy. The mean bone mineral density of the spine and femur increased significantly. Monthly intravenous pamidronate therapy decreased frequencies of fracture and increased bone mineral density without significant adverse events in Korean patients with osteogenesis imperfecta.

Identification of novel mutations of the HADHA and HADHB genes in patients with mitochondrial trifunctional protein deficiency.

Patients with long-chain 3-hydroxyacyl coenzyme A dehydrogenase (LCHAD) deficiency manifest hypoketotic hypoglycemia, hepatomegaly, hypotonia, lactic acidemia, acute renal failure, cardiomyopathy, and sudden death. We describe four novel mutations of the alpha- and beta-subunits of the mitochondrial trifunctional protein in four patients from three unrelated families. Their plasma acylcarnitine profiles suggested the presence of LCHAD deficiency by demonstrating highly elevated 3-hydroxyacyl carnitines by tandem mass spectrometry (MS/MS). Patients 1 and 2 had siblings who had died of lactic acidemia during the neonatal period. These patients also manifested lactic acidemia and died in the neonatal period. Patient 3 had a family history of Reye-like syndrome. She exhibited acute renal failure, rhabdomyolysis, pericardial effusion, and myopathy at the age of 12 years. DNA analysis of patients 1 and 2 revealed homozygosity for a c.1689+2T>G mutation of the HADHA gene, resulting in the skipping of exon 16 with an in-frame 69-bp deletion. Patient 3 was a compound heterozygosity of the HADHB gene, N307D/N389D. Patient 4, a 25-month-old baby, manifested recurrent episodes of lethargy, metabolic acidosis, elevated liver enzymes, and dark urine from the age of 10 months. Mutation analysis of the HADHB gene of patient 4 identified compound heterozygosity of N114D/N307D.

Comparison of clinical, radiological and molecular findings in Korean infants and children with achondroplasia and hypochondroplasia.

Achondroplasia (ACH) and hypochondroplasia (HCH) share clinical features characterized by disproportionate short stature with rhizomelic shortening of the limbs. In an attempt to clarify genotype-phenotype correlation in ACH and HCH, we investigated the presence of the previously identified mutations of FGFR3 in 26 patients with ACH- or HCH-mimicking features and compared clinical and radiographic findings between the two groups. Using genomic DNA sequencing and RFLP analysis, G380R, an ACH-specific mutation, and N540K, an HCH-specific mutation, were detected in 13 patients (50%) and five patients (19%), respectively. No mutations of FGFR3 were detected in eight patients (31%). No remarkable clinical or radiological differences were evident among the ACH infants and children with G380R, the HCH patients with N540K, and the patients without verified mutations. These results suggest that genotype-based diagnosis needs to precede proper genetic counseling for patients with ACH or HCH, which show very similar clinical and radiological features.

Endocrine manifestations of chromosome 22q11.2 microdeletion syndrome.

BACKGROUND: Endocrine abnormalities, including hypocalcemia, thyroid dysfunction, and short stature, are associated with chromosome 22q11.2 microdeletion syndrome. This study was undertaken to examine the frequencies and clinical features of endocrine abnormalities in patients with 22q11.2 microdeletion syndrome. METHODS: We analyzed 61 patients with 22q11.2 microdeletion syndrome diagnosed based on the verification of microdeletion by fluorescent in situ hybridization (FISH) using a probe of the DiGeorge syndrome critical region (TUPLE1) at 22q11.2 and a control probe, ARSA at 22q13. Serum total calcium, phosphorus, and intact parathyroid hormone (PTH) levels were measured, thyroid function test was performed, and serum IGF-1 and IGFBP-3 levels were also estimated. Height and weight of patients were compared with individual chronological ages. RESULTS: Hypocalcemia was found in 20 patients (32.8%), and overt hypoparathyroidism in 8 (13.1%). Two patients (3.3%) showed autoimmune thyroid diseases, 1 each with Graves' disease and Hashimoto thyroiditis. Ten patients (16.4%) were below the third percentile in height, but the serum IGF-1 level was normal in 9 out of these 10 patients. CONCLUSION: Our findings show that patients with chromosome 22q11.2 microdeletion syndrome present with variable endocrine manifestations and variable clinical phenotypes. In addition to FISH analysis, careful endocrine evaluations are required in patients with this microdeletion syndrome, particularly for those with hypoparathyroidism or thyroid dysfunction.

Identification of novel mutations of the DAX-1 gene in patients with X-linked adrenal hypoplasia congenita.

OBJECTIVE: X-linked adrenal hypoplasia congenita (AHC) is a condition clinically featuring adrenal insufficiency and hypogonadotropic hypogonadism caused by mutations of DAX-1. This study was undertaken to characterize the molecular defects of DAX-1 in 3 unrelated Korean patients with AHC. PATIENTS AND METHODS: Patient 1 is a 6-year-old boy who presented with a salt-losing adrenal crisis in the neonatal period. Patient 2 is a 3-year-old boy who manifested aspiration pneumonia and adrenal insufficiency at the age of 1 month. Patient 3 is a 7-year-old boy who developed an adrenal crisis at the age of 3 days. In each of these patients, DAX-1 was analyzed by direct DNA sequencing after polymerase chain reaction amplification of the entire coding region. RESULTS: Direct sequencing of DAX-1 revealed two novel mutations, 1156_1157delCT in patient 1 and another novel nonsense mutation W105X in patient 2. Patient 3 had complete deletion of DAX-1. In patient 3, serum transaminases and creatine kinase levels were elevated while the glycerol kinase activity of leukocytes was decreased. Markedly elevated glycerol excretion was detected by urine organic acid analysis. Patient 3 was diagnosed as Xp21 contiguous gene syndrome associated with deletions of the entire IL1RAPL, GK genes and the C-terminal region of DMD gene. CONCLUSIONS: Two novel mutations of DAX-1 were detected in 2 unrelated patients with AHC, and complete deletion of DAX-1 in a patient with Xp21 contiguous gene syndrome who also presented with glycerol kinase deficiency, Duchenne muscular dystrophy, and AHC.