Hyperinsulinemic Hypoglycemia and Growth Hormone Deficiency Secondary to 20p11 Deletion.

Hypoglycemia is concerning for neurological complications in infants and children. Determining the cause of hypoglycemia is essential in providing appropriate treatment. Hyperinsulinism and growth hormone deficiency are known causes of hypoglycemia but are not commonly found together. We report a 4-month-old boy who presented with severe hypoglycemia and was found to have both hyperinsulinism and growth hormone deficiency. Treatment with both recombinant human growth hormone and diazoxide led to blood glucose normalization. Subsequently, he was found to have a genetic diagnosis of 20p11.22p11.21 deletion. 20p11 deletions have been associated with hypopituitarism, most commonly seen in growth hormone deficiency causing hypoglycemia. This case is one of a few to report hyperinsulinism as a manifestation of this deletion.

Variations in Morning Serum Cortisol Levels Based on Sex and Pubertal Status.

INTRODUCTION: Patients with suspected adrenal insufficiency undergo screening with a serum morning cortisol level and confirmatory testing with an adrenocorticotropic hormone (ACTH) stimulation test. However, much of the data collected to determine appropriate values for morning cortisol levels are derived from adult populations and may not accurately represent pediatric physiology. The purpose of this study was to evaluate the mean morning cortisol level in the pediatric population based on pubertal status and sex in order to better understand such influences on laboratory evaluation of adrenal insufficiency. METHODS: A retrospective chart review was conducted using electronic medical records of patients seen at Children's Mercy Kansas City from 11/01/2007 to 11/01/2017. Patients between 2 and 18 years of age who had pubertal staging assessed by a pediatric endocrinologist and confirmed adrenal sufficiency by high-dose ACTH stimulation testing were included. Two-sample Wilcoxon rank sum (Mann-Whitney) tests or t tests were used to compare morning cortisol levels between females and males - both independent of Tanner stage and by Tanner stage. Multivariable regression models were used to evaluate associations among covariates on two outcomes: morning cortisol levels and peak cortisol values with ACTH stimulation. RESULTS: Morning cortisol levels were greater in females than males independent of Tanner staging (p = 0.0054) and also in Tanner stage 1 (p = 0.0042). No differences in mean morning cortisol levels between Tanner stage 2-5 females and males were found (p = 0.4652). Morning cortisol levels were not significantly different between Tanner 1 patients and Tanner 2-5 patients independent of sex (p = 0.0575). Sex was predictive of serum morning cortisol levels (p = 0.015), and morning cortisol levels were predictive of peak cortisol levels during ACTH stimulation testing (p < 0.001). CONCLUSIONS: These data suggest that different normative cortisol values may need to be established for pediatric females and males, and by pubertal status. Larger prospective studies are needed to evaluate the role of sex and pubertal status in identifying adrenal insufficiency in the -pediatric population.

A New Paediatric Diabetes Knowledge Test - M-WIKAD Development and Factor Analysis.

Purpose: The purpose of this study was to develop a measure of type 1 diabetes mellitus (T1DM) knowledge that is aimed at youth and is based on contemporary management standards. Methods: An 88-item test was derived from the American Association of Diabetes Educators 7 Self-Care Behaviors. Results: A multidisciplinary team selected the best 49 items which were piloted in a sample of 119 youths (59 males, aged 12-18, having a mean ± standard deviation glycated haemoglobin (A1C) of 9.9%±1.80 (84.7±19.7 mmol/mol). A minimum absolute point-biserial correlation coefficient of 0.250 was used to choose 49 items from the original 88 questions. Categorical principal component analysis was then used to identify the best factor analytical model that consisted of five factors composed of 19 items. These five factors explained 57% of item variances. Factors were associated with the latent variables: advanced problem-solving, hypoglycaemia prevention and management, taking insulin/medication administration, daily management and healthy active living. Conclusion: A new T1D knowledge test for youth was refined from 88 to 49 questions based on expert opinion and empirical test construction. The instrument was then refined to 19 items based on exploratory factor analysis. Future goals are to validate this factor model with another cohort and confirm concurrent validity based on youth's glycated haemoglobin and adherence behaviours. Our new T1DM knowledge measure initially appears valid and promising as a new clinical and research tool.

Employing a results-based algorithm to reduce laboratory utilization in ACTH stimulation testing.

BACKGROUND: The High Dose Adrenocorticotropic Hormone (ACTH) Stimulation Test is the gold standard to diagnose adrenal insufficiency. Normal adrenal function is defined as a peak cortisol response to pharmacologic stimulation with cosyntropin of ≥18 µg/dL. Our practice was to obtain cortisol levels at 0, 30 and 60 min after cosyntropin administration. Once a value of ≥18 µg/dL has been obtained, adrenal insufficiency is ruled out and there is little diagnostic utility in subsequent stimulated levels. METHODS: We aimed to decrease laboratory utilization by developing a results-based algorithm in the electronic medical record (EMR). Cortisol levels were analyzed on the 0 and 60 min samples; then an EMR discern rule automatically generated an order to analyze the 30-min sample if the 60-min cortisol level was subnormal. RESULTS: Exclusion of adrenal insufficiency was excluded using one stimulated cortisol level in 8% prior to algorithm development. After several plan-do-study-act cycles, 99% of normal tests were performed using only one stimulated cortisol level. CONCLUSIONS: This laboratory-based algorithm resulted in reduced laboratory utilization, and aligned our practice to recommendations of the Pediatric Endocrine Society. Similar algorithms could be created for other dynamic tests to reduce unnecessary laboratory utilization.

A novel AVPR2 splice site mutation leads to partial X-linked nephrogenic diabetes insipidus in two brothers.

UNLABELLED: X-linked nephrogenic diabetes insipidus (NDI, OMIM#304800) is caused by mutations in the arginine vasopressin (AVP, OMIM*192340) receptor type 2 (AVPR2, OMIM*300538) gene. A 20-month-old boy and his 8-year-old brother presented with polyuria, polydipsia, and failure to thrive. Both boys demonstrated partial DDAVP (1-desamino-8-D AVP or desmopressin) responses; thus, NDI diagnosis was delayed. While routine sequencing of AVPR2 showed a potential splice site variant, it was not until exome sequencing confirmed the AVPR2 splice site variant and did not reveal any more likely candidates that the patients' diagnosis was made and proper treatment was instituted. Both patients were hemizygous for two AVPR2 variants predicted in silico to affect AVPR2 messenger RNA (mRNA) splicing. A minigene assay revealed that the novel AVPR2 c.276A>G mutation creates a novel splice acceptor site leading to 5' truncation of AVPR2 exon 2 in HEK293 human kidney cells. Both patients have been treated with high-dose DDAVP with a remarkable improvement of their symptoms and accelerated linear growth and weight gain. CONCLUSION: We present here a unique case of partial X-linked NDI due to an AVPR2 splice site mutation; patients with diabetes insipidus of unknown etiology may harbor splice site mutations that are initially underestimated in their pathogenicity on sequence analysis. WHAT IS KNOWN: • X-linked nephrogenic diabetes insipidus is caused by AVPR2 mutations, and disease severity can vary depending on the functional effect of the mutation. What is New: • We demonstrate here that a splice site mutation in AVPR2 leads to partial X-linked NDI in two brothers. • Treatment with high-dose DDAVP led to improvement of polyuria and polydipsia, weight gain, and growth.

Type 2 diabetes mellitus in children and adolescents.

On the basis of strong research evidence and consensus, type 1 diabetes mellitus (DM) remains the most common form of DM in children and adolescents. The incidence of type 2 DM in the pediatric population is rapidly increasing because of the obesity epidemic, and minority groups are disproportionately affected. (2) (10) (19) On the basis of some research evidence and consensus, it can be challenging to initially differentiate between type 2 DM and type 1 DM clinically because of the increased prevalence of obesity, the complex interplay of autoimmunity and obesity, and common symptoms at presentation. (1) (10) (19) Significant evidence and consensus support a genetic basis for the development of type 2 DM in children. Physicians should routinely screen at risk children older than age 10 years for DM. Screening criteria include obesity, a family history of type 2 DM, a minority racial or ethnic background, acanthosis nigricans, or other diseases associated with insulin resistance, including polycystic ovary syndrome, hypertension, or dyslipidemia. (1) (10) (18) (19) On the basis of consensus, diagnosis of type 2 DM can be confirmed by an elevated fasting blood glucose level greater than 126 mg/dl (7.0 mmol/L), an elevated 2-hour plasma glucose greater than 200 mg/dL (11.1 mmol/L) on an oral glucose tolerance test, an elevated random blood glucose greater than 200 mg/dL (11.1 mmol/L), or a hemoglobin A1c level greater than 6.5% with suggestive symptoms. (10) According to strong research evidence and consensus, once the diagnosis has been made, treatment should be based on the acuity of presentation and should focus on lifestyle modification and on normalizing hyperglycemia to minimize complications. Metformin is currently first-line treatment for type 2 DM in children and adolescents older than age 10 years who present nonacutely. (18) (19) Strong research evidence and consensus demonstrate that because type 2 DM has an insidious onset, microvascular and macrovascular complications can be present at the time of diagnosis. Patients should be screened for the presence of complications when the diagnosis of type 2 DM is made and in follow-up. (6) (10).

Human conjunctival epithelial cells lack lipopolysaccharide responsiveness due to deficient expression of MD2 but respond after interferon-gamma priming or soluble MD2 supplementation.

Inflammatory responses to Gram-positive and Gram-negative bacterial cell wall components are initiated by Toll-like receptor 2 (TLR2) and TLR4, respectively. Therefore, the existence of functionally active TLR2 and TLR4 in human conjunctival epithelial cells (HCEC) are critical for the effective host defense against bacterial infections in the eye. We examined the ability of HCEC to respond to TLR4 ligand, lipopolysaccharide (LPS), or TLR2 ligands, lipoteichoic acid (LTA) and peptidoglycan (PGN) using the Chang conjunctival epithelial cell line and the primary conjunctival epithelial cell line (IOBA-NHC) as in vitro models. Incubation of Chang cells with LPS (1 to 1,000 ng/ml) failed to stimulate IL-6 production where as stimulation with LTA or PGN resulted in marked increases in IL-6 production. Semi-quantitative RT-PCR and immunofluorescence analyses showed that Chang cells express TLR2 and TLR4 mRNA and proteins. However, these cells expressed little or no mRNA encoding MD2, an accessory molecule required for TLR4 signaling. Incubation of Chang epithelial cells with interferon-gamma (IFNgamma), but not TNF-alpha, stimulated MD2 mRNA expression and restored LPS responsiveness. In addition, when Chang cell cultures were supplemented with soluble MD2, LPS was able to stimulate IL-6 production. The lack of LPS response, deficient expression of MD2, and induction of MD2 expression and LPS response after IFNgamma priming, were also evident in IOBA-NHC cells. These results demonstrate that HCEC lack LPS responsiveness due to deficient expression of MD2 and that the response can be restored by IFN-gamma priming or MD2 supplementation.