SCUBE3 loss-of-function causes a recognizable recessive developmental disorder due to defective bone morphogenetic protein signaling.

Signal peptide-CUB-EGF domain-containing protein 3 (SCUBE3) is a member of a small family of multifunctional cell surface-anchored glycoproteins functioning as co-receptors for a variety of growth factors. Here we report that bi-allelic inactivating variants in SCUBE3 have pleiotropic consequences on development and cause a previously unrecognized syndromic disorder. Eighteen affected individuals from nine unrelated families showed a consistent phenotype characterized by reduced growth, skeletal features, distinctive craniofacial appearance, and dental anomalies. In vitro functional validation studies demonstrated a variable impact of disease-causing variants on transcript processing, protein secretion and function, and their dysregulating effect on bone morphogenetic protein (BMP) signaling. We show that SCUBE3 acts as a BMP2/BMP4 co-receptor, recruits the BMP receptor complexes into raft microdomains, and positively modulates signaling possibly by augmenting the specific interactions between BMPs and BMP type I receptors. Scube3-/- mice showed craniofacial and dental defects, reduced body size, and defective endochondral bone growth due to impaired BMP-mediated chondrogenesis and osteogenesis, recapitulating the human disorder. Our findings identify a human disease caused by defective function of a member of the SCUBE family, and link SCUBE3 to processes controlling growth, morphogenesis, and bone and teeth development through modulation of BMP signaling.

Relation of glomerular filtration to insulin resistance and related risk factors in obese children.

BACKGROUND AND OBJECTIVE: Childhood obesity is associated with later development of significant renal morbidity. We evaluated the impact of the degree of insulin sensitivity on estimated glomerular filtration rate (eGFR) and determined the factors associated with eGFR in obese children. We further tested the relation of eGFR to clinical outcomes such as blood pressure and microalbuminuria. MATERIALS AND METHODS: We evaluated the relation of whole body insulin sensitivity and estimated glomerular filtration rate (eGFR) across the spectrum of obesity in children and adolescents. eGFR was calculated using the iCARE formula, which has been validated in obese children with varying glucose tolerance. RESULTS: 1080 children and adolescents with overweight and obesity (701 females and 379 males) participated. Insulin sensitivity was a strongly negatively associated with (B = -2.72, p < 0.001) eGFR), even after adjustment for potential confounders. Male sex emerged to be significantly associated with eGFR with boys having greater values than girls (B = 18.82, p < 0.001). Age was a positively associated (B = 2.86, p < 0.001) with eGFR. Whole body and hepatic insulin sensitivity decreased across eGFR quartiles. Adjusted eGFR was tightly positively associated with systolic blood pressure (B = 0.09, p = 0.003) and negatively associated with the presence of microalbuminuria (B = -2.18, p = 0.04). CONCLUSIONS: eGFR tends to increase with greater degrees of insulin resistance in children and adolescents representing hyperfiltration and is associated with cardiovascular risk factors. Longitudinal studies are needed to determine the natural history of childhood insulin resistance related hyperfiltration in regards to future kidney disease.

Alarming increase in ketoacidosis in children and adolescents with newly diagnosed type 1 diabetes during the first wave of the COVID-19 pandemic in Israel.

OBJECTIVE: To evaluate the incidence and severity of ketoacidosis (DKA) at type 1 diabetes diagnosis during the first wave of the coronavirus disease 2019 (COVID-19) pandemic in Israel. RESEARCH DESIGN AND METHODS: A population-based study the product of a national collaboration of Israeli pediatric diabetes centers investigated the presentation of childhood-onset type 1 diabetes. The frequencies of DKA and severe DKA observed during the COVID-19 period from March 15, 2020 (commencement of the first nationwide lockdown) until June 30, 2020 were compared with the same periods in 2019, 2018, and 2017 using multivariable logistic regression, adjusting for age, sex, and socioeconomic position. RESULTS: During the COVID-19 period, DKA incidence was 58.2%, significantly higher than in 2019 (adjusted OR [aOR] 2.18 [95% CI, 1.31-3.60], P = 0.003); 2018 (aOR 2.05 [95% CI, 1.26-3.34], P = 0.004); and 2017 (aOR, 1.79 [95% CI, 1.09-2.93], P = 0.022). The incidence of severe DKA was 19.9%, significantly higher than in 2018 (aOR, 2.49 [95% CI, 1.20-5.19], P = 0.015) and 2017 (aOR, 2.73 [95% CI, 1.28-5.82], P = 0.009). In 2020, admissions and duration of stay in the intensive care unit were higher than in previous years (P = 0.001). During the COVID-19 pandemic, children aged 6-11 years had higher incidences of DKA (61.3% vs. 34.0%, 40.6%, and 45.1%, respectively, P = 0.012), and severe DKA (29.3% vs. 15.1%, 10.9%, and 5.9%, respectively, P = 0.002). CONCLUSIONS: The dramatic increase in DKA at presentation of childhood-onset type 1 diabetes during the COVID-19 pandemic mandates targeted measures to raise public and physician awareness.

Eligibility for growth hormone therapy in children born small for gestational age is substantially lower than expected.

BACKGROUND: Growth hormone therapy is indicated for children who are both born 'small for gestational age' (SGA) and do not achieve adequate catch-up growth (ACUG). OBJECTIVE: To evaluate the actual incidence of infants born SGA and their actual ACUG. METHODS: Birth weight data from the newborn registry at two hospitals were analysed during four consecutive years. SGA was defined according to WHO parameters and the corresponding Israeli criteria. Follow-up measurements of height and weight were abstracted from either the Ministry of Health-child growth follow-up centres, or their paediatrician clinic. ACUG was declared when the height reached was above -2.5 or -2 standard deviations (SDS) from the mean for age and gender. RESULTS: Out of 43 307, only 524 babies in the cohort (1.2%) were SGA (52% of expected). This finding was consistent annually. Out of the 446 SGA born children with available growth data (85%) during 4-8 years, 405 children (90.8%) reached a height greater than -2SDS and 428 (96%!) reached a height greater than -2.5 SDS. Term children had higher rate of ACUG achievement as compared to preterm 97.2% vs 86.8% (P < .001). Birth week and birth weight were also related to achievement of ACUG (P < .001). CONCLUSION: This large representative, heterogeneous and Western Caucasian cohort indicates that the actual number of SGA newborns is nearly half of the expected and that the actual prevalence of ACUG is also significantly higher than previously reported. These findings may have an impact on morbidity, health cost planning and growth hormone requirements in SGA babies.

Insights into Central Congenital Hypothyroidism: A Multicenter Retrospective Analysis.

CONTEXT: Central congenital hypothyroidism (CCH) is a thyroid hormone deficiency at birth caused by inadequate pituitary stimulation of the thyroid gland. Although primary CH has been studied extensively, studies on CCH are sparse. OBJECTIVES: To assess the prevalence of CCH in Israel and describe its clinical features, neonatal screening results, and outcomes. DESIGN: Multicenter cross-sectional retrospective chart review. SETTING: Nine pediatric endocrine units throughout Israel. PATIENTS: Patients diagnosed with CCH in 1987-2021 were categorized into early (within 14 days of life) and late (after 14 days) diagnosis groups. Newborn screening (NBS) results were retrospectively retrieved from the national NBS program dataset. RESULTS: CCH prevalence in Israel was about 1:42,800 live births. Subjects were 94 patients (54 males), of these, 84% had multiple pituitary hormone deficiencies and 16% had isolated CCH. The median age at diagnosis was 50 days (range, 1-8760), with 66% having moderate to severe hypothyroidism. NBS detected only three infants. Early diagnosis occurred in 34% due to hypopituitarism, while 66% were diagnosed later due to growth and developmental delays. Neurodevelopmental sequelae included mental retardation (12%), learning difficulties (18%), delayed speech (27%), and motor clumsiness (19%), with no significant differences in outcomes between early and late diagnosis. CONCLUSIONS: Despite high rates of neurodevelopmental sequelae, no differences were found between early and late diagnosis groups. Further research is needed to assess the impact of delayed diagnosis on neurological outcomes in newborns with CCH. Improved strategies for detecting CHH in newborns are also necessary.

Adipose Tissue Insulin Resistance Is Not Associated With Changes in the Degree of Obesity in Children and Adolescents.

CONTEXT: The "carbohydrate-insulin model" claims that adipose tissue insulin sensitivity explains development of obesity via adipocyte energy storage and/or low postprandial metabolic fuel levels. OBJECTIVE: We tested whether adipose tissue insulin sensitivity predicts changes in the degree of obesity over time. METHODS: This secondary analysis of an observational study of youth with obesity included 213 youths at a pediatric weight management clinic. Adipose tissue insulin sensitivity/resistance and whole-body insulin sensitivity were evaluated using oral glucose tolerance test (OGTT)-derived surrogates in the face of changes in the degree of obesity over time. The main outcome measure was change in body mass index (BMI) z score. RESULTS: Mean BMI z change was 0.05 ± 0.28 (range, -1.15 to 1.19), representing a broad distribution of changes in the degree of obesity over a follow-up period of 1.88 ± 1.27 years. Adipose tissue insulin resistance was not associated with changes in the degree of obesity in univariate or multivariate analyses (adjusted for baseline age, BMI z score, sex, ethnicity, and time of follow-up). Low postprandial free fatty acid concentrations or their suppression during the OGTT were not associated with changes in the degree of obesity in univariate or multivariate analyses. Whole-body insulin sensitivity was not associated with changes in the degree of obesity in univariate or multivariate analyses. CONCLUSION: In this secondary analysis, in youth with obesity, adipose tissue insulin resistance is not protective from increases of the degree of obesity and skeletal muscle insulin resistance is not associated with increases of the degree of obesity.The analysis was performed using data derived from NCT00000112 and NCT00536250.

Bariatric Surgery in Adolescents with Obesity: Long-Term Perspectives and Potential Alternatives.

BACKGROUND: Severe obesity among adolescent shows a worrisome trend in regard to its increasing prevalence and poses a great challenge for treatment. Conservative measures have modest effects on weight loss, usually fail in achieving a sustainable weight loss and resolution of comorbidities. This has led to greater utilization of bariatric surgery (BS) that offers a fast reduction in body mass index with little perioperative complications. Despite the increasing utilization of BS, data are still insufficient, regarding their long-term outcome in adolescents. We review short- and long-term effects of BS and their implications on bone health and nutritional deficiencies in adolescents. In addition, we discuss possible pharmaceutical alternatives. SUMMARY: BS results in a substantial weight loss of roughly 37% in the first-year post-operation and is superior to conservative measures in resolution of metabolic comorbidities. BS significantly improves health-related quality of life. Longer follow-up (F/U) shows weight regain in 50% of patients. Furthermore, reduced bone mass and nutritional deficiencies were reported in up to 90% of patients. Most recently, alternative to BS became more relevant with approval of GLP-1 analogues use in adolescents. GLP-1 analogues are potent enough to induce moderate clinically meaningful weight loss and improvement of metabolic component. KEY MESSAGES: We conclude that obese adolescents without major obesity-related complications may benefit from pharmacological interventions with lifestyle modification. We advise considering BS as treatment approach in adolescents with severe obesity and major obesity-related complications with proper preoperative preparation and postoperative F/U in excellence centers.

Lack of Evidence for a Causal Role of Hyperinsulinemia in the Progression of Obesity in Children and Adolescents: A Longitudinal Study.

OBJECTIVE: The carbohydrate-insulin model (CIM) claims that chronic exposure to hyperinsulinemia induced by dietary carbohydrates explains development of obesity via direct effects of insulin and/or low postprandial metabolic fuel levels. We aimed at testing whether indices of hyperinsulinemia and postprandial glucose levels can predict increases in the degree of obesity over time. RESEARCH DESIGN AND METHODS: Children and adolescents with obesity attending a pediatric obesity clinic performed oral glucose tolerance tests (OGTTs) and received standard obesity management. Indices of hyperinsulinemia and insulin secretion were derived from the OGTT and evaluated in the face of changes in the degree of obesity over time. RESULTS: A total of 591 children (217 males and 374 females) participated, and the mean follow-up was 1.86 ± 1.29 years. OGTT-derived area under the curve of insulin, peak insulin, fasting insulin, the insulinogenic index, or insulin at 30 min were not associated with greater changes in the degree of obesity in univariate or multivariate analyses (adjusted for baseline age, BMI z score, sex, and ethnicity). Low postprandial glucose <75 mg/dL was not associated with greater changes in the degree of obesity in univariate or multivariate analyses. In a subsample of 104 participants with a follow-up >4 years, none of these parameters was associated with greater increases in the degree of obesity. CONCLUSIONS: In children and adolescents with obesity, exposure to hyperinsulinemia, greater insulin secretion, or low postprandial glucose is not associated with greater increases in the degree of obesity over 2-4 years. The CIM should be evaluated in children with lower BMI and for longer follow-up periods.

Expanding the spectrum of endocrinopathies identified in Schaaf-Yang syndrome - A case report and review of the literature.

Schaaf-Yang syndrome is a genetic disorder caused by mutations in the paternal allele of the MAGEL2 gene. Developmental delay, feeding difficulties, joint contractures and a high prevalence of autism spectrum disorders are characteristic of the syndrome. Endocrine abnormalities include mostly various pituitary hormonal deficiencies, presenting as hypoglycemia in 48% of reported cases. Persistent hyperinsulinism was only described in two siblings and responded to diazoxide treatment. We describe a unique case of an infant with Schaaf-Yang syndrome that presented with persistent hyperinsulinism unresponsive to diazoxide. Furthermore, we conducted a literature review of the endocrine abnormalities described in MAGEL2 related disorders. The case presented expands the clinical phenotype of Schaaf-Yang syndrome and emphasizes the importance of endocrine follow-up in these patients. Further investigation into the role of MAGEL2 in the regulation of pancreatic beta-cell insulin secretion, will improve our understanding of the abnormalities in glucose regulation in this syndrome.