Hormone Research in Paediatrics最新文献

Introduction: Resistance to thyroid hormones (RTH) is a rare but important genetic cause of decreased peripheral tissue responses to the actions of thyroxine. Most RTH cases are caused by mutations in thyroid hormone receptor β (TRβ, THRB), while a few are caused by mutations in thyroid hormone receptor α (TRα, THRA). RTH is clinically heterogeneous, and the biochemical features are often confusing, resulting in misdiagnoses, mismanagement, and life-long consequences for affected individuals. An awareness of the clinical and genetic spectrum of RTH is therefore essential to avoid misdiagnosis and to ensure timely referral for definitive management.

Case presentation: Here we present four clinical vignettes describing three children and one adult with RTH encountered in our "real-world" tertiary pediatric endocrinology practice. We describe a novel THRA (NM_199334.3:c.-298 + 5G>A) missense mutation in the first intron in the 5' untranslated region (UTR) of THRA, with causal variant prediction with Combined Annotation Dependent Depletion placing the mutation in the top 1% most deleterious variants (scaled C-score 21.7). We speculate that this mutation causes an exon skipping event affecting the 5'UTR and protein-coding region, thereby resulting in abnormal or absent TRα1, although supporting clinical, genetic, and/or functional analyses are required to upgrade the pathogenicity classification from uncertain significance to pathogenic/likely pathogenic. The three cases describing "classical" RTH caused by THRB mutations showcase the consequences of misdiagnosis, with 2 patients prescribed medications that could exacerbate symptoms and one child presenting with behavioral problems that might benefit from tailored management with hormone therapies.

Conclusion: This report not only highlights the importance of a high index of suspicion for RTH to prompt the genetic diagnosis but also contributes to a growing appreciation of the pathogenic role of non-coding variants in rare diseases.

Type 1 diabetes (T1D) presents a significant global health challenge, characterized by immune-mediated destruction of pancreatic beta-cells. Achieving therapeutic goals such as prevention of immune destruction, preservation of beta-cell mass, and automated insulin delivery remains complex due to the disease's heterogeneity. This review explores the advancements and challenges in beta-cell replacement therapies, including pancreas and islet cell transplantation, stem cell-derived β-cell generation, and biotechnological innovations. Pancreas transplantation, especially simultaneous pancreas and kidney transplantation (SPK), has evolved significantly, offering insulin independence and improved quality of life despite surgical and immunological complications. Allogeneic islet transplantation, though less invasive, faces challenges such as donor scarcity, immunosuppressive therapy, and variable long-term success. Innovations in stem cell therapy, particularly using human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs), promise an unlimited source of β-cells. However, translating these advances into clinical applications involves overcoming technical, biological, and ethical hurdles. Strategies such as immunomodulation, encapsulation, and genetic engineering are critical to enhancing the viability and integration of transplanted cells. This review provides a comprehensive overview of the scientific intricacies and potential of β-cell replacement therapies, emphasizing the need for continued research to address the remaining challenges and improve diabetes care outcomes.

Introduction: The long-term effect of the COVID-19 pandemic on body weight has not been sufficiently analyzed. This study aimed to analyze changes in body mass index (BMI) during and after the COVID-19 pandemic among a large pediatric population attending health care clinics.

Methods: This retrospective longitudinal cohort study utilized electronic medical data of 106,871 children (52.1% males, median age 8.2 years at pre-pandemic assessment). Each child had at least one BMI measurement recorded pre-pandemic and two additional measurements: one during the pandemic and one post-pandemic.

Results: Obesity rates increased from 12.8% pre-pandemic to 15.4% during the pandemic, slightly decreasing to 15.0% post-pandemic. BMI-standard deviation scores (SDSs) increased during the pandemic, in both sexes, across all ages and all socioeconomic position (SEP) clusters, and in children with pre-pandemic underweight or normal weight (all P<0.001). Post-pandemic, BMI-SDS decreased but remained above pre-pandemic levels, particularly in younger children (aged 2-6 years) and those from low/medium SEP clusters (all P<0.001). BMI-SDS continued to increase in children aged 6.1-16 years, those of Arab ethnicity, and those in the high SEP cluster.

Conclusions: The COVID-19 pandemic correlated with an overall increase in BMI-SDS, which decreased post-pandemic but remained above pre-pandemic levels. Effective policy interventions to prevent pediatric obesity are crucial.

Introduction: Managing exercise remains challenging for adolescent athletes with type 1 diabetes (T1D), especially in contact sports. Even the use of hybrid closed loops can cause problems due to the need to disconnect the pump during some training or competitions. This study evaluated the efficacy of a novel protocol for the use of an advanced hybrid closed-loop system in adolescent football players with T1D during a sports camp.

Methods: Eleven boys aged 14.9 years (25-75th percentile: 14-15.5), with a diabetes duration of 5.7 years (5.2-7) and regular training schedules in junior football leagues, participated in the study. They started AHCL (MiniMed780G, Medtronic) therapy a month before a week-long sports camp and were observed during the sports camp and the preceding week. Daily camp activities included two 1.5-h training sessions. Protocol included a 90-min temporary target of 150 mg/dL before and insulin pump disconnection during training. Physical activity was tracked using wGT3X-BT Actigraph monitors.

Results: The camp provided conditions of demanding physical activity (6.6 [6-6.9] h/day of moderate-to-vigorous intensity). After starting AHCL, the average participant time spent in the target glucose range (70-180 mg/dL) was 79.34 ± 8.46%, and no significant change was observed during the camp (mean difference +0.79 ± 8.24%, p = 0.7581). Median glucose levels dropped by 10.91 ± 12.08 mg/dL (p = 0.0134), and time in the tight target range increased by 11.41 ± 11.60% (p = 0.0008) without increasing the time below range (<70 mg/dL) or glycemic variability. During the camp, daily insulin dose and basal/bolus ratio remained comparable with baseline, but the relative amount of automated bolus insulin decreased by 14.24 ± 4.65% (p < 0.0001).

Conclusion: The predefined regimen, including a temporary target before and disconnection of AHCL during football training, was safe and may provide satisfactory glucose control in active adolescents with T1D. This protocol could be adapted for use in other intensive contact sports.

Introduction: Congenital central hypoventilation syndrome (CCHS) is a rare autosomal dominant condition due to mutations in the transcription factor PHOX2B. It is characterized by alveolar hypoventilation with symptoms of autonomic nervous system dysfunction. Hyperinsulinaemic hypoglycaemia (HH) due to glucose dysregulation caused by anomalous insulin secretion has been reported as a feature of CCHS. However, HH and glycaemic outcomes in the context of CCHS have not been characterized in longitudinal follow-up. We describe the variable phenotype of glucose dysregulation and glycaemic outcomes in children with CCHS.

Case presentation: We report 6 children with PHOX2B mutation-positive CCHS diagnosed with HH in a national cohort from two UK congenital hyperinsulinism specialist centres. We describe the initial presentation, the challenges in management, and glycaemic outcomes in longitudinal follow-up. All patients were term infants diagnosed with CCHS in the neonatal period due to PHOX2B mutations and required long-term ventilation by tracheostomy. HH was diagnosed at a median age of 222 days (median, range 36-594) with postprandial hypoglycaemia (4/6 patients) or fasting hypoglycaemia (2/6 patients). Two patients were treated with diazoxide monotherapy; one with diazoxide and overnight continuous gastrostomy feeds; one with acarbose; and two with dietary manifestations and use of continuous glucose monitoring sensor. Three patients who presented earlier in the observation period demonstrated a reduction in the severity of HH over time, leading to hypoglycaemia resolution at a median age of 4.8 years (range 4.45-5.5 years).

Conclusion: Patients with CCHS, due to PHOX2B mutations, may experience both fasting and postprandial hypoglycaemia, necessitating treatment for HH. Clinicians should screen children with CCHS for hypoglycaemia symptoms to quickly identify those affected by HH, initiate prompt treatment, and prevent potential brain injury from severe hypoglycaemia. The severity of hypoglycaemia due to HH tends to decrease over time, with glycaemic resolution potentially being achieved over several years.

Introduction: Severe childhood obesity can be caused by pathogenic variants in several genes involved in monogenic and syndromic obesity. Recently, heterozygous variants in pleckstrin homology domain interacting protein (PHIP) have been identified in patients with obesity as part of Chung-Jansen syndrome.

Case presentation: The index patient is a 5-year-old boy with severe obesity since 1 year of age, developmental delay, facial dysmorphism, and behavior problems. Whole-exome sequencing identified a novel missense variant in PHIP (c.3182C>A, p.Ala1061Glu) in the index patient. Further genetic testing in family members revealed segregation of the same PHIP variant in the brother and mother, who both presented with severe childhood obesity and developmental delay or learning difficulties. The PHIP missense variant was predicted pathogenic by multiple in silico tools and affects a highly conserved residue.

Conclusion: Early-onset obesity may be monogenic. Our finding expands the spectrum of disease-causing variants in PHIP and demonstrates variable intrafamilial clinical expressivity and severity. Screening for PHIP variants should be included in genetic testing in patients with severe early-onset obesity.

Introduction: Vosoritide is a C-type natriuretic peptide (CNP) analog that binds its receptor on chondrocytes, promoting growth by inhibiting the ERK1/2-MAPK pathway. We previously reported the results of a phase II study in children with hypochondroplasia. Vosoritide led to an average increase in annualized height velocity (AHV) of 1.81 cm/year and gain of 0.36 in height standard deviation (SD) over 12 months. We present here the pharmacokinetic/pharmacodynamic (PK/PD) data from this study and examine the correlations between these parameters and growth outcomes.

Methods: We conducted a phase II trial of daily subcutaneous vosoritide (15 μg/kg/day) in 24 prepubertal subjects with hypochondroplasia (12 females, mean age 5.9 ± 2.3 years, mean height -3.29 + 0.68 SD). Plasma vosoritide levels were assayed using an electrochemiluminescence assay. PD markers including serum collagen X biomarker (CXM) and urine cyclic guanosine monophosphate (cGMP) production were measured at day 1, month 6, and month 12 visits. Pearson correlations and regression analyses were performed between PK and PD parameters and growth outcomes.

Results: Vosoritide PK parameters were similar to those previously reported in patients with achondroplasia. CXM levels increased from a baseline mean of 22.5 ± 6.5 to 41.6 ± 15.9 ng/mL after 12 months of treatment (p < 0.0001). Urine cGMP increased within 1 h and peaked at 2 h after injection. The mean AUC for cGMP production was not significantly different at each study visit. The maximum change in cGMP AUC correlated with PK AUC (r = 0.46, p = 0.0001). However, drug exposure, as measured by average PK AUC, did not correlate with any growth outcome. CXM levels correlated with the prior 6-month interval height velocity (partial correlation coefficient = 0.40, p = 0.0048). However, change in CXM did not correlate with change in height velocity or change in height SD during treatment.

Conclusions: Vosoritide treatment showed improvement in AHV and height SD in children with hypochondroplasia. PK analysis indicates that drug exposure was correlated to global CNP activity as measured by urine cGMP but did not correlate with growth outcomes. More studies are needed to identify specific patient characteristics that can predict response to therapy and clinical outcomes.

Introduction: Precocious puberty is defined as the appearance of secondary sexual characteristics before the age of 8 years in girls and 9 years in boys. Central precocious puberty (CPP) is a rare condition that is diagnosed when premature activation of the hypothalamic-pituitary-gonadal axis is detected, in association with precocious breast development or testicular growth. Idiopathic CPP is historically considered to be the most common form, but in recent years defects in a small but growing number of genes regulating the timing of puberty have been identified in an increasing proportion of cases of CPP. Delta-like non-canonical Notch ligand 1 (DLK1) is understood to be one of the key genes involved in the etiology of CPP, although its mechanistic role is not yet fully understood.

Case presentation: We identified a novel de novo variant of DLK1 (c.835C>T; p.Gln279*) in an 8-year-old girl of Bangladeshi origin. She presented with an advanced Tanner staging of B4P4A2, significantly advanced bone age (BA, 13 years), a near-adult proportioned uterus, with a history of menarche at the age of 7.4 years. Diagnosis was confirmed by raised basal luteinizing hormone concentration. She was found to have truncal obesity associated with abnormal fasting insulin levels and mildly elevated cholesterol levels. These findings are consistent with previous literature describing an association between patients with DLK1 deficiency and an impaired metabolic profile. The patient was treated for 2 years with GnRH agonists with ongoing biochemical follow-up into adolescence.

Conclusion: This case illustrates the susceptibility to metabolic derangement for patients with mutations in DLK1 and the need for ongoing monitoring after puberty. Our summary of previously identified DLK1 variants and their metabolic consequences demonstrates the frequency of obesity, lipid abnormalities, and insulin dysregulation in this patient cohort in childhood and beyond. This knowledge can guide future clinical practice for patients with CPP patients due to DLK1 deficiency.

Introduction: Diabetic ketoacidosis (DKA) is the leading cause of mortality among youth with type 1 diabetes (T1D). Guidelines for DKA prevention exist; however, specific guidance about when to check ketones and how to manage youth using insulin pumps and automated insulin delivery (AID) systems is lacking.

Methods: A 35-item online survey exploring clinical ketone management practices for youth with T1D in the USA was distributed to diabetes healthcare professionals (HCPs). Survey responses, including multiple-choice and Likert scale questions, were summarized and rates of agreement and disagreement (Likert scale 4, 5 vs. 1, 2, 3) are reported.

Results: In total, 123 HCPs (51% physicians, 26% diabetes educators, 19% nurse practitioners) from 47 institutions completed the survey. Seventy percent worked at academic specialty centers. Ninety-seven percent reported >50% continuous glucose monitoring use in their clinic and 72% reported >50% insulin pump use. Although 79% reported having ketone management protocols, the level and duration of hyperglycemia at which ketone monitoring was advised ranged from >200 to 350 mg/dL and from 0 min to >6 h of duration. While 72% had distinct ketone management protocols for pump users, only 29% had specific protocols for AID. Sixty-two percent agreed that DKA due to infusion site failure was a significant problem in their practice, and 70% agreed there was a need to standardize ketone management guidelines.

Conclusions: The preventable nature and high incidence of DKA highlight the need to build consensus for clinical ketone management and to develop tools to facilitate management, especially as the use of diabetes technologies continues to increase.