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PURPOSE: Maturity-onset diabetes of the young (MODY) is a subtype of type 2 diabetes characterized by autosomal-dominant inheritance and early onset. The pathophysiology of MODY is primarily defective insulin secretion resulting from mutations in at least 6 different genes. Most affected patients harbour mutations in either GCK (encoding glucokinase, also called MODY2) and HNF1A (encoding hepatic nuclear factor-1alpha, also called MODY3). We studied Canadian probands to determine if they had mutations in MODY2 or MODY3 genes. METHOD: We used genomic DNA sequencing of probands from 9 previously unreported Canadian MODY families. RESULTS: Five MODY probands had mutations in HNF1A, of which 4 were novel (namely IVS5-1delTAG, E275fsdelGAAG, F268S and L44fsdelC) and 4 had mutations in GCK, of which 2 were novel (E237K and L324P). These mutations expand the spectrum of MODY mutations and bring the total number of Canadian MODY families that have been molecularly defined in our laboratory to 15 (8 MODY3 and 7 MODY2). CONCLUSION: Because of the growing evidence that molecular diagnosis may affect prognosis and treatment, this information may be important in future for Canadian MODY families and their physicians. [ABSTRACT FROM AUTHOR]

Monocarboxylate transporter 8 (MCT8) deficiency is a rare, X-linked disorder arising from mutations in the SLC16A2 gene and resulting from dysfunctional thyroid hormone transport. This disorder is characterized by profound neurodevelopmental delay and motor disability due to a lack of thyroid hormone in the brain, and coexisting endocrinological symptoms, due to chronic thyrotoxicosis, resulting from elevated thyroid hormone outside the central nervous system (CNS). In February 2024, we reviewed the published literature to identify relevant articles reporting on the current unmet needs of patients with MCT8 deficiency. There are several main challenges in the diagnosis and treatment of MCT8 deficiency, with decreased awareness and recognition of MCT8 deficiency among healthcare professionals (HCPs) associated with misdiagnosis and delays in diagnosis. Diagnostic delay may also be attributed to other factors, including the complex symptomology of MCT8 deficiency only becoming apparent several months after birth and pathognomonic serum triiodothyronine (T3) testing not being routinely performed. For patients with MCT8 deficiency, multidisciplinary team care is vital to optimize the support provided to patients and their caregivers. Although there are currently no approved treatments specifically for MCT8 deficiency, earlier identification and diagnosis of this disorder enables earlier access to supportive care and developing treatments focused on improving outcomes and quality of life for both patients and caregivers., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Bauer, Auble, Clark, Hu, Isaza, McNerney, Metzger, Nicol, Pierce and Sidlow.)

Un nombre croissant de jeunes s'identifient comme transgenres ou de diverses identités de genre. De nombreux pédiatres et dispensateurs de soins de première ligne accueilleront cette population dans leur pratique, dans le cadre de soins liés au genre ou de soins de santé généraux. Le présent document de principes se veut une ressource pour orienter les pédiatres et les dispensateurs de soins de première ligne à adopter une approche d'affirmation pour la prestation des soins réguliers à tous les jeunes. De plus, il contient de l'information visant à aider les dispensateurs à répondre aux demandes de conseils des jeunes transgenres et de diverses identités de genre et de leur famille au sujet des possibilités de transition médicale et d'orientation vers des services spécialisés s'ils le désirent et le jugent pertinent. Enfin, on anticipe que la demande de soins d'affirmation de genre continue d'augmenter, et certains dispensateurs de soins peuvent souhaiter acquérir les connaissances et les habiletés nécessaires pour amorcer les inhibiteurs d'hormones et les hormones d'affirmation de genre chez les adolescents. Le présent document ne contient pas de directives cliniques, mais de l'information fondamentale au sujet des divers éléments possibles des soins d'affirmation de genre, tout en reconnaissant que les besoins et les objectifs d'adolescents particuliers n'incluent pas automatiquement de telles interventions. D'autres ressources permettant d'acquérir les compétences nécessaires pour offrir des interventions d'affirmation de genre sont également proposées., (© Société canadienne de pédiatrie 2023. Publié par Oxford University Press pour le compte de la Société canadienne de pédiatrie. Tous droits réservés. Pour obtenir une autorisation, écrivez à journals.permissions@oup.com.)

Increasing numbers of youth identify as transgender or gender-diverse (TGD). Many paediatricians and primary care providers (PCPs) will encounter this population in their practice, either for gender-related care or general health needs. This statement is intended as a resource to guide paediatricians and PCPs in implementing an affirming approach to routine health care provision for all youth. Furthermore, it presents information to assist providers in responding to requests for counselling from TGD youth and their families around potential options for medical transition, and in making referrals to specialized services, if desired and relevant. Finally, as demand for gender-affirming care is anticipated to continue to increase, some health care providers (HCPs) may wish to develop the knowledge and skills required to initiate adolescents on hormone-blocking agents and gender-affirming hormones. This document is not intended to be a clinical practice guideline, but will provide foundational information regarding these potential components of gender-affirming care, recognizing that the needs and goals of individual adolescents may or may not include such interventions. Additional resources relevant to developing the expertise required to provide gender-affirming interventions will also be identified., Competing Interests: The authors have no conflicts to declare., (© Canadian Paediatric Society 2023. Published by Oxford University Press on behalf of the Canadian Paediatric Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

To examine the (i) relationships between various body mass index (BMI)-derived metrics for measuring severe obesity (SO) over time based the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) references and (ii) ability of these metrics to discriminate children and adolescents based on the presence of cardiometabolic risk factors. In this cohort study completed from 2013 to 2021, we examined data from 3- to 18-year-olds enrolled in the CANadian Pediatric Weight management Registry. Anthropometric data were used to create nine BMI-derived metrics based on the CDC and WHO references. Cardiometabolic risk factors were examined, including dysglycemia, dyslipidemia, and elevated blood pressure. Analyses included Pearson correlations, intraclass correlation coefficients (ICC), and receiver operator characteristic area-under-the-curve (ROC AUC). Our sample included 1,288 participants (n = 666 [52%] girls; n = 874 [68%] white). The prevalence of SO varied from 60-67%, depending on the definition. Most BMI-derived metrics were positively and significantly related to one another (r = 0.45-1.00); ICCs revealed high tracking (0.90-0.94). ROC AUC analyses showed CDC and WHO metrics had a modest ability to discriminate the presence of cardiometabolic risk factors, which improved slightly with increasing numbers of risk factors. Overall, most BMI-derived metrics rated poorly in identifying presence of cardiometabolic risk factors.    Conclusion: CDC BMI percent of the 95 th percentile and WHO BMIz performed similarly as measures of SO, although neither showed particularly impressive discrimination. They appear to be interchangeable in clinical care and research in pediatrics, but there is a need for a universal standard. WHO BMIz may be useful for clinicians and researchers from countries that recommend using the WHO growth reference. What is Known: • Severe obesity in pediatrics is a global health issue. • Few reports have evaluated body mass index (BMI)-derived metrics based on the World Health Organization growth reference. What is New: • Our analyses showed that the Centers for Disease Control and Prevention BMI percent of the 95 th percentile and World Health Organization (WHO) BMI z-score (BMIz) performed similarly as measures of severe obesity in pediatrics. • WHO BMIz should be a useful metric to measure severe obesity for clinicians and researchers from countries that recommend using the WHO growth reference., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background and Objectives: Referrals of transgender and gender-diverse (trans) youth to medical clinics for gender-affirming care have increased. We described characteristics of trans youth in Canada at first referral visit., Methods: Baseline clinical and survey data (2017-2019) were collected for Trans Youth CAN!, a 10-clinic prospective cohort of n = 174 pubertal and postpubertal youth <16 years with gender dysphoria, referred for hormonal suppression or hormone therapy, and 160 linked parent-participants. Measures assessed health, demographics, and visit outcome., Results: Of youth, 137 were transmasculine (assigned female) and 37 transfeminine (assigned male); 69.0% were aged 14 to 15, 18.8% Indigenous, 6.6% visible minorities, 25.7% from immigrant families, and 27.1% low income. Most (66.0%) were gender-aware before age 12. Only 58.1% of transfeminine youth lived in their gender full-time versus 90.1% of transmasculine ( P < .001). Although transmasculine youth were more likely than transfeminine youth to report depressive symptoms (21.2% vs 10.8%; P = .03) and anxiety (66.1% vs 33.3%; P < .001), suicidality was similarly high overall (past-year ideation: 34.5%, attempts: 16.8%). All were in school; 62.0% reported strong parental gender support, with parents the most common support persons (91.9%). Two-thirds of families reported external gender-related stressors. Youth had met with a range of providers (68.5% with a family physician). At clinic visit, 62.4% were prescribed hormonal suppression or hormone therapy, most commonly depot leuprolide acetate., Conclusions: Trans youth in Canada attending clinics for hormonal suppression or gender-affirming hormones were generally healthy but with depression, anxiety, and support needs., Competing Interests: POTENTIAL CONFLICT OF INTEREST: The authors have indicated they have no potential conflicts of interest to disclose., (Copyright © 2021 by the American Academy of Pediatrics.)

Background: Screening studies have shown that 0.7-4.5% of generally healthy children have isolated diastolic high BP. We therefore studied the characteristics of children with diastolic BP in the elevated and hypertensive ranges according to current guidelines in US children from the National Health and Nutrition Examination Survey (NHANES, 1999-2016)., Methods: We studied 17,362 children (8-18 years) with BP measured by sphygmomanometry. High BP was categorized as isolated systolic (iSH), isolated diastolic (iDH), or Mixed., Results: Overall, 86.0% (95% CI =  85.0-87.0) of the population had normal BP, 8.7% (8.0-9.3) elevated BP, 4.9% (4.4-5.5) Stage 1, and 0.4% (0.4-0.6) Stage 2. Moreover, 11.1% (10.3-12.0) had iSH, 1.9% (1.5-2.2) iDH, and 1.0% (0.8-1.2) Mixed. Children with iDH were more likely to be female, younger, white, and leaner than those with iSH, with lower rates of overweight/obesity. iDH was generally between normals and iSH. Resting heart rate was significantly higher in iDH even after adjustment for known covariates., Conclusions: Children with iDH may have a distinct clinical picture. A leaner habitus and higher resting heart rate may reflect differences in underlying pathophysiology. Longitudinal follow-up studies are needed to better define the pathogenesis, progression, and long-term prognosis in iDH., Impact: Using gold-standard auscultation and 2017 guidelines, isolated diastolic high BP (iDH) is found in 1.9% (95% CI 1.5-2.2) of American children; these children are younger, leaner, more female, and have fewer cardiometabolic risks. Resting heart rate is significantly higher in iDH compared to both normals and iSH even after adjustments for known covariates. Autonomic hyperactivity in iDH may speak to both etiology and therapeutic approaches. iDH appears to be a distinct clinical phenotype characterized by differences in anthropometric measures, sex, age, and resting heart rate. Follow-up studies are clearly needed to clarify its pathogenesis, progression, and prognosis., (© 2021. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.)

Question: Previous research has indicated that rapid rehydration in children with type 1 diabetes who present with diabetic ketoacidosis could result in cerebral edema. I have been treating patients with diabetic ketoacidosis with gradual fluid replacement. With the risk of cerebral injury in these patients, should I continue management with slow fluid rehydration?, Answer: Recent research has shown that neither fluid infusion rate nor sodium chloride concentration increases risk of cerebral injury. However, it is possible for subtle brain injury to occur during treatment, regardless of the fluid administration strategy. The 2018 International Society for Pediatric and Adolescent Diabetes guidelines have been updated in light of this research., (Copyright© the College of Family Physicians of Canada.)

Background: We assess the impact of the 2017 American Academy of Pediatrics (AAP) guidelines on the prevalence of high blood pressure (BP) in generally healthy Canadian children and identify risk factors associated with high BP (elevated, stage 1, or stage 2 at a single visit)., Methods: A cohort of 7,387 children aged 6 to 18 years in the Canadian Health Measures Survey (CHMS, 2007 to 2015) had BPTru oscillometry with centiles and stages assigned using both the 2017 AAP guidelines and the 2004 Fourth Report from the National Institute of Health/National Heart Lung and Blood Institute (NIH/NHLBI)., Results: Although both shifted upwards significantly, mean population systolic BP and diastolic BP percentiles are now 24.2 (95% confidence interval: 23.3 to 25.2) and 46.4 (45.3 to 47.6). As a result, the population prevalence of high BP increased from 4.5% (3.9 to 5.2, NIH/NHLBI) to 5.8% (5.0 to 6.6, AAP), less than in US children measured by auscultation (14.2%, 13.4 to 15.0). Children with high BP were more likely to be overweight/obese, to be exposed to prenatal/household smoking, and to have hypertriglyceridemia, without differences in dietary salt, infant breastfeeding, neonatal hospitalizations, or exercise frequency., Conclusion: The 2017 AAP guidelines increase the prevalence of high BP in Canadian children; Canadian prevalence appears lower than in the USA. This may reflect differences in measurement methods or in the prevalence of childhood overweight/obesity between countries, that is, 31.1% (28.9 to 33.3) versus 40.6% (39.5 to 42.0), respectively. Those with high BP were more likely to have other cardiac risk factors, including overweight/obesity, prenatal/household smoking exposure, and hypertriglyceridemia., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Canadian Paediatric Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Transitional neonatal hypoglycemia is common in at-risk well newborns, requires immediate attention, interferes with breastfeeding, and frequently results in separation of mothers from their babies. Breastfeeding shortly after birth and screening at-risk newborns at 2 hours of age is standard practice in Canada. In the Sugar Babies Trial, a custom-made 40% glucose-gel massaged to the buccal mucosa in at-risk infants decreased intravenous glucose treatment, but not neonatal intensive care unit admission. It increased the rate of full breastfeeding after discharge but experts suggest that additional evidence is needed. Further, commercially available neonatal glucose-gels do not exist, so practitioners around the world have started using diabetes-care products, which do not meet standards for use in newborns. Here, we provide a condensed summary of the topic and of management alternatives., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Canadian Paediatric Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: Type 1 diabetes (T1D) is a chronic source of metabolic and neuropsychological stress, which may eventually lead to autonomic neuropathy and other complications related to micro- and macro-vasculopathies. We aimed to investigate the relationship between T1D chronic stress and autonomic response to acute stress testing that was expected being affected by chronic stress., Methods: Twenty youths with confirmed diagnosis of T1D were assessed. Chronic stress assessment included hemoglobin A1c (HbA1c) ≥7.5%, psychological stress assessed by perceived stress scale (PSS), hypoglycemic events, and proinflammatory cytokines. The acute stress testing used standardized stress video games. Autonomic response to acute stress was assessed by the amplitude and direction of changes in heart rate variability. Analyses determined correlations between changes in parasympathetic nervous system during stress testing and chronic diabetes stressors., Results: A strong correlation was found between the amplitude of high frequency (HF) changes and HbA1c values (ρ = 0.74, P < .001). Youths with HbA1c ≥7.5% showed a larger amplitude of HF changes during acute stress (49% vs 16%, P < .001) and a higher PSS score (22.5 vs 19.0, P = .003), compared to those with HbA1c <7.5%. Additionally, among youths with HbA1c ≥7.5%, those with positive changes in HF had a lower level of IL-8 than those with negative changes (5.40 vs 7.85 pg/mL, P = .009)., Conclusions: Study findings support the need for better understanding the health effects of stress-related autonomic dysfunction in youth with T1D., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Importance: Based on the new 2017 blood pressure guidelines, the prevalence of high blood pressure (BP) among adults has increased from 32% to 46%. Based on new norms and diagnostic thresholds that better align with adult definitions, new clinical practice guidelines were also published for children. The American Academy of Pediatrics clinical practice guidelines for the management of elevated BP in children replace the 2004 fourth report from the National Heart, Lung, and Blood Institute., Objectives: To assess the consequences of the American Academy of Pediatrics clinical practice guidelines for the management of elevated BP in children on the prevalence and severity of elevated BP among children and to characterize risk factors for children with new-onset hypertension or a worsening in clinical stage ("reclassified upward")., Design, Setting, and Participants: This study applied both sets of guidelines to classify BP in 15 647 generally healthy, low-risk children aged 5 to 18 years from National Health and Nutrition Examination Surveys (from January 1, 1999, to December 31, 2014). In the case-control portion of the study, children whose BP was reclassified upward (cases) were matched for sex, age, and height with controls with normal BP. Anthropometric and laboratory risk factors were compared, and age- and sex-specific z scores for weight, waist circumference, and body mass index were calculated. Blood pressure was measured by auscultation by trained personnel. After the child rested quietly for 5 minutes, 3 to 4 consecutive BP readings were recorded., Main Outcomes and Measures: Blood pressure percentiles and clinical classification based on either the 2017 American Academy of Pediatrics guidelines or the 2004 National Heart, Lung, and Blood Institute report., Results: Among the 15 647 children in the study (7799 girls and 7848 boys; mean [SD] age, 13.4 [2.8] years), based on the American Academy of Pediatrics guidelines, the estimated (weighted) population prevalence of elevated BP increased from 11.8% (95% CI, 11.1%-13.0%) to 14.2% (95% CI, 13.4%-15.0%). Overall, 905 of 15 584 children (5.8%) had newly diagnosed hypertension (n = 381) or a worsening in clinical stage (n = 524), which represents a substantial increase in disease burden for the health care system. Children whose BP was reclassified upward were more likely to be overweight or obese, with higher z scores for weight, waist circumference, and body mass index. The prevalence of abnormal laboratory test results was also increased, with adverse lipid profiles and increased hemoglobin A1c levels (prediabetes)., Conclusions and Relevance: Clustering of cardiovascular risk factors in otherwise healthy US children suggests that those whose BP was reclassified represent a high-risk population whose cardiovascular risk may previously have been underestimated.

Objectives: The Public Health Agency of Canada has officially adopted growth charts from the World Health Organization (WHO); nevertheless, North American blood pressure (BP) Z-scores and percentiles still depend on height Z-scores based on growth charts from the US Centers for Disease Control (CDC), which may differ significantly, particularly in toddlers. Since many practitioners simply replace CDC height scores with WHO equivalents for diagnosing hypertension, we explore the impact of this substitution on BP Z-scores in real-world BPs measured on more than 22,000 children aged 2 to 18 years., Methods: We report agreement between two different measures of the same quantity as Bland-Altman limits of agreement (LOA)., Results: In toddlers aged 2 to 5 years, WHO height Z-scores are systematically lower with a bias (mean error) of -0.30 SD, and the 95% LOA range from -0.51 to -0.10 SD. Despite this difference, systolic BP Z-scores were nearly identical (bias = 0.06, LOA = 0.02 to 0.10). For older children and diastolic BP Z-scores, the errors were smaller still, and agreement was equally good for hypotensive, normotensive and hypertensive measurements., Conclusions: Clinicians may safely use WHO height charts when calculating BP Z-scores or percentiles against the National Institute of Health's National Heart, Lung, and Blood Institute reference data.

Objective: To review adherence to a provincial diabetic ketoacidosis (DKA) protocol and to assess factors associated with intravenous fluid administration and the length time on an insulin infusion., Methods: A retrospective chart review was conducted of all DKA admissions to British Columbia Children's Hospital (BCCH) during September 2008 to December 2013. Data collection included diabetes history, estimation of dehydration, insulin and fluid infusion rates, and frequency of laboratory investigations. Markers of adherence included appropriate use of a fluid bolus, normal saline and insulin infusion time, fluid intake and outputs, and the frequency of blood work during the insulin infusion. A log-linear regression model was fitted to assess the factors associated with insulin infusion duration., Results: Of 157 children (median [interquartile range] age: 10.6 years [5.0, 13.8]) hospitalized for DKA, 45% (n = 70) were male, 55% (n = 86) were transferred from other hospitals, and 26% (n = 40) were admitted to intensive care unit. Thirty-five percent of subjects estimated to have mild or moderate dehydration received fluid boluses. In the adjusted analysis, the average duration on DKA protocol was 39% (95% confidence interval [CI]: 12%, 67%) longer for children admitted with severe dehydration (compared to those with mild dehydration)., Conclusions: Health care providers' adherence to the BCCH DKA protocol is poor. More severe dehydration at presentation is associated with longer duration of insulin infusion. Further knowledge translation initiatives focused on accurate estimation of volume depletion to ensure appropriate initial fluid resuscitation-as well as careful monitoring during DKA hospitalization-are important, especially in community centers., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Glycogen storage disease type 1 is an autosomal recessive disorder with an incidence of 1 in 100,000. Long-term complications include chronic blood glucose lability, lactic academia, short stature, osteoporosis, delayed puberty, gout, progressive renal insufficiency, systemic or pulmonary hypertension, hepatic adenomas at risk for malignant transformation, anemia, vitamin D deficiency, hyperuricemic nephrocalcinosis, inflammatory bowel syndrome (type 1b), hypertriglyceridemia, and irregular menstrual cycles. We describe hypogonadotropic hypogonadism as a novel complication in glycogen storage disease (GSD) type 1. Case Studies and Methods: Four unrelated patients with GSD 1a (N = 1) and 1b (N = 3) were found to have hypogonadotropic hypogonadism diagnosed at different ages. Institutional Research Ethics Board approval was obtained as appropriate. Participant consent was obtained. A retrospective chart review was performed and clinical symptoms and results of investigations summarized as a case series., Results: All patients were confirmed biochemically to have low luteinizing hormone (LH) and follicular stimulating hormone (FSH), and correspondingly low total testosterone. Clinical symptoms of hypogonadism varied widely. Investigations for other causes of hypogonadotropic hypogonadism were unremarkable. In addition, all patients were found to have disproportionately low bone mineral density at the lumbar spine compared to the hip. Common to all patients was erratic metabolic control, including recurrent hypoglycemia and elevated lactate levels., Discussion: Recurrent elevations in cortisol in response to hypoglycemia may be the underlying pathology leading to suppression of gonadotropin-releasing hormone (GnRH) release. Incorporating clinical and/or biochemical screening of the hypothalamic-pituitary-gonadal axis may be important in the management of this disease. Testosterone therapy however needs to be carefully considered because of the risk of hepatic adenomas.

Background: In adults, anthropometric measures of central adiposity, such as waist-height ratio (WHtR) and waist circumference (WC), are more strongly associated with cardio-metabolic risks than BMI., Methods: To provide similar quantitative tools for North American children, we created smoothed centile charts and LMS tables for WHtR and WC based on data from the US National Health and Nutrition Survey, cycle III (NHANES III, N = 11,930 aged 2-24 y 1988-1994)., Results: Applying these reference charts to subsequent NHANES survey cycles, 1999-2012) demonstrated a significant mean increase in both Z-scores of approximately 0.30 SD. In measuring the strength of the association between anthropometric measures and cardio-metabolic risk factors, a unit change in Z-scores for WHtR, WC, and BMI significantly increased the odds of an adverse outcome in all cases (1.18-2.03, P < 0.0001). Z-scores for both measures of central adiposity were significantly more strongly associated with cardio-metabolic comorbidities than BMI-Z., Conclusion: Since Z-scores permit standardized comparisons across ages and genders, they are useful measures of central adiposity in both clinical or research settings. By providing LMS tables for children and adolescents based on North American reference data, we hope to provide quantitative tools for the study of obesity and its complications.

Diabetes requiring insulin is increasingly common and likely to impact students in most, if not all, schools. Diabetes and its complications have major personal, social and economic impact, and improved diabetes control reduces the risk of both short- and long-term complications. Evidence shows that more intensive management of diabetes - through frequent blood glucose monitoring, insulin administration with injections and/or insulin pumps, and careful attention to diet and exercise - leads to better control. Since children spend 30 to 35 hours per week at school, effectively managing their diabetes while there is integral to their short- and long-term health. The Canadian Paediatric Society and the Canadian Pediatric Endocrine Group recommend that minimum standards for supervision and care be established across Canada to support children and youth with type 1 diabetes in schools. These recommendations are derived from evidence-based clinical practice guidelines, with input from diabetes care providers from across Canada, and are consistent with the Canadian Diabetes Association's Guidelines for the Care of Students Living with Diabetes at School.

Context: Most cases of autosomal dominant hypoparathyroidism (ADH) are caused by gain-of-function mutations in CASR or dominant inhibitor mutations in GCM2 or PTH., Objective: Our objectives were to identify the genetic basis for ADH in a multigenerational family and define the underlying disease mechanism., Subjects: Here we evaluated a multigenerational family with ADH in which affected subjects had normal sequences in these genes and were shorter than unaffected family members., Methods: We collected clinical and biochemical data from 6 of 11 affected subjects and performed whole-exome sequence analysis on DNA from two affected sisters and their affected father. Functional studies were performed after expression of wild-type and mutant Gα11 proteins in human embryonic kidney-293-CaR cells that stably express calcium-sensing receptors., Results: Whole-exome-sequencing followed by Sanger sequencing revealed a heterozygous mutation, c.179G>T; p.R60L, in GNA11, which encodes the α-subunit of G11, the principal heterotrimeric G protein that couples calcium-sensing receptors to signal activation in parathyroid cells. Functional studies of Gα11 R60L showed increased accumulation of intracellular concentration of free calcium in response to extracellular concentration of free calcium with a significantly decreased EC50 compared with wild-type Gα11. By contrast, R60L was significantly less effective than the oncogenic Q209L form of Gα11 as an activator of the MAPK pathway. Compared to subjects with CASR mutations, patients with GNA11 mutations lacked hypercalciuria and had normal serum magnesium levels., Conclusions: Our findings indicate that the germline gain-of-function mutation of GNA11 is a cause of ADH and implicate a novel role for GNA11 in skeletal growth.

Objective: To describe patient characteristics at presentation, treatment, and response to treatment in youth with gender dysphoria., Study Design: A retrospective chart review of 84 youth with a diagnosis of gender dysphoria seen at BC Children's Hospital from 1998-2011., Results: Of the 84 patients, 45 (54%) identified as female-to-male (FtM), 37 (44%) as male-to-female (MtF), and 2 (2%) as natal males who were undecided. Median age of presentation was 16.9 years (range 11.4-19.8 years) and 16.6 years (range 12.3-22.5 years) for FtM and MtF youth, respectively. Gonadotropin-releasing hormone analog treatment was prescribed in 27 (32%) patients. One FtM patient developed sterile abscesses with leuprolide acetate; he was switched to triptorelin and tolerated this well. Cross-sex hormones were prescribed in 63 of 84 patients (39 FtM vs 24 MtF, P < .02). Median age at initiation of testosterone injections in FtM patients was 17.3 years (range 13.7-19.8 years); median age at initiation of estrogen therapy in MtF patients was 17.9 years (range 13.3-22.3 years). Three patients stopped cross-sex hormones temporarily due to psychiatric comorbidities (2 FtM) and distress over androgenic alopecia (1 FtM). No severe complications were noted in patients treated with testosterone or estrogen., Conclusion: Treatment with gonadotropin-releasing hormone analog and/or cross-sex hormones, in collaboration with transgender-competent mental health professionals, is an intervention that appears to be appropriate in carefully selected youth with gender dysphoria. Long-term follow-up studies are needed to determine the safety of these treatments in this age group., (Copyright © 2014 Mosby, Inc. All rights reserved.)

Background: For ages 5-19 years, the World Health Organization (WHO) publishes reference charts based on 'core data' from the US National Center for Health Statistics (NCHS), collected from 1963-75 on 22,917 US children. To promote the use of body mass index in older children, weight-for-age was omitted after age 10. Health providers have subsequently expressed concerns about this omission and the selection of centiles. We therefore sought to extend weight-for-age reference curves from 10 to 19 years by applying WHO exclusion criteria and curve fitting methods to the core NCHS data and to revise the choice of displayed centiles., Methods: WHO analysts first excluded ~ 3% of their reference population in order to achieve a "non-obese sample with equal height". Based on these exclusion criteria, 314 girls and 304 boys were first omitted for 'unhealthy' weights-for-height. By applying WHO global deviance and information criteria, optimal Box-Cox power exponential models were used to fit smoothed weight-for-age centiles. Bootstrap resampling was used to assess the precision of centile estimates. For all charts, additional centiles were included in the healthy range (3 to 97%), and the more extreme WHO centiles 0.1 and 99.9% were dropped., Results: In addition to weight-for-age beyond 10 years, our charts provide more granularity in the centiles in the healthy range -2 to +2 SD (3-97%). For both weight and BMI, the bootstrap confidence intervals for the 99.9th centile were at least an order of magnitude wider than the corresponding 50th centile values., Conclusions: These charts complement existing WHO charts by allowing weight-for-age to be plotted concurrently with height in older children. All modifications followed strict WHO methodology and utilized the same core data from the US NCHS. The additional centiles permit a more precise assessment of normal growth and earlier detection of aberrant growth as it crosses centiles. Elimination of extreme centiles reduces the risk of misclassification. A complete set of charts is available at the CPEG web site (http://cpeg-gcep.net).

Background: Young adult survivors of paediatric brain tumours (PBTs) who have been treated with radiation therapy will likely be severely growth hormone-deficient when retested at the achievement of final height. Growth hormone replacement therapy (GHRT) is administered to treat growth hormone deficiency (GHD). Public drug coverage for GHRT falls under the responsibility of provincial governments across Canada. This study sought to determine the extent of public drug coverage and cost in each Canadian province for GHRT to treat GHD during adulthood for young adult survivors of PBTs., Methods: Data were collected from provincial government resources and drug formularies from 2012-2013 on the extent of coverage for GHRT based on a clinical case scenario representative of a young adult survivor of a PBT with childhood-onset radiation-induced GHD, the ingredient cost for GHRT and the applicable provincial public drug plan cost-sharing policies. A model was then created to simulate out-of-pocket costs incurred by a young adult male and a young adult female survivor of a PBT for one year of GHRT in each province with applicable cost-sharing arrangements and levels of low annual individual total income that best represent the majority of young adult survivors of PBTs. Out-of-pocket costs were expressed as a percentage of annual income. Comparisons were made between provinces descriptively, and variation among provinces was summarized statistically., Results: Alberta, Manitoba, Ontario, Quebec, New Brunswick, and Newfoundland and Labrador provide coverage for GHD during adulthood on a case-by-case basis, while British Columbia, Saskatchewan, Nova Scotia and Prince Edward Island provide no coverage. The percentage of annual income to fund GHRT across the provinces without public coverage ranged from 14.4% to 25.5% for males and 21.5% to 38.3% for females, and with public coverage was 0.0% to 4.1% for males and 0.0% to 5.0% for females., Interpretation: There are considerable out-of-pocket costs and variation in coverage provided by provincial public drug plans to fund GHRT for young adult survivors of PBTs with GHD. The implementation of a national drug formulary could potentially prevent undue financial hardship and remove disparities resulting from variations in provincial drug plans., (Copyright © 2014 Longwoods Publishing.)

Objectives: B7-H4 is a negative coregulatory molecule known to be involved in immune response. We study here B7-H4 expression and its possible role in diabetes and cancer development., Methods: Formalin-fixed, paraffin-processed pancreas samples from patients with type 1 diabetes (T1D), insulinoma, pancreatic ductal adenocarcinoma (PDAC), and normal organ donors were studied by bright-field and multifluorescence immunohistochemistry to examine B7-H4 expression and its colocalization with islet endocrine hormones. Quantitative RT-PCR and Western blot assay were used to examine B7-H4 mRNA and protein expression in the islet and exocrine tissues from normal donors and pancreatic cancer cell lines., Results: B7-H4 protein expression in islet β cells is decreased in T1D and PDAC, but increased in insulinoma patients when compared to normal controls; the changes in B7-H4 expression are concomitant with insulin expression on the islet β cells. The insulin/B7-H4 colocalization on the β cells, expressed in colocalization coefficient Pearson r, is also changed in these islets., Conclusions: Our observation of altered B7-H4 expression, concomitant with insulin expression, in the pancreatic islets of T1D, PDAC, and insulinoma patients when compared to normal controls suggests that B7-H4 pathway might play an important role in maintenance of β-cell function, but its exact role remains to be explored.

The Canadian Pediatric Endocrinology Group (CPEG) has produced complementary growth curves based on the 2010 'WHO Growth Charts for Canada'. In response to concerns from CPEG members and the general paediatric community regarding the presentation of the WHO data, complementary curves were generated, which the authors believe will enhance clarity, reduce potential errors in classification and enable users to better track short-term changes, particularly for weight in older children. Specifically, these curves extend weight-for-age beyond 10 years of age, restore additional percentiles within the normal range, remove extreme percentiles and harmonize the choice of body mass index percentiles with adult definitions of overweight and obesity. All modifications followed strict WHO methodology and used core data from the United States National Center for Health Statistics. The curves retain the clean appearance of the 2010 Canadian curves and are available from the CPEG website (http://cpeg-gcep.net).

Background: Allograft rejection is one of the main obstacles for islet transplantation. B7-H4 plays a key role in maintaining T-cell homeostasis by reducing T-cell proliferation and cytokine production. In this study, we investigated whether the endogenous expression of B7-H4 in β cells from B7-H4 transgenic mice enhances islet allograft survival., Methods: B7-H4 transgenic C57BL/6 (B6) mice (RIP.B7-H4) were developed by inserting the entire B7-H4 open reading frame under the rat insulin promoter (RIP). B7-H4 protein expression was examined by flow cytometric analysis and immunohistochemical staining. Islet allograft survival was investigated in streptozotocin-induced diabetic recipient BALB/c (H-2d) mice transplanted with 400 islets from RIP.B7-H4 (H-2b) mice under the kidney capsule. The recipient control group received islets from wild-type B6 donors., Results: B7-H4 protein was significantly up-regulated in isolated islets from RIP.B7-H4 compared with wild-type B6 mice (56%±23% vs. 3%±1.2%). B7-H4 was coexpressed with insulin, but not glucagon, suggesting that B7-H4 is expressed in a β-cell-specific manner. Recipient BALB/c mice transplanted with RIP.B7-H4 islets established euglycemia for 42.3±18.4 days (mean±SD; n=9) compared with controls at 23.1±7.8 days (mean±SD; n=12; P<0.004, log-rank test)., Conclusions: The endogenous expression of B7-H4 in donor β cells from transgenic mice prolongs islet allograft survival, confirming the negative role of B7-H4 in regulating alloreactive T-cell responses.

Background: Obesity, age and hormone imbalances including hypothyroidism and growth hormone deficiency and therapy, but not gonadotropin-releasing hormone agonist (GnRHa) therapy, have been identified as risk factors for slipped capital femoral epiphysis (SCFE). Five of 7 reported cases describe SCFE in children shortly after GnRHa therapy cessation., Methods: We report 3 cases of SCFE that occurred in children on GnRHa therapy for the treatment of central precocious puberty (CPP) and discuss possible promoting factors., Results: An otherwise healthy 8.75-year-old girl [body mass index (BMI) Z score +1.75] developed SCFE 6.75 years into GnRHa therapy for idiopathic CPP. A second girl (with a history of acute lymphoblastic leukemia requiring total body irradiation) was 10.6 years old (BMI Z score +1.06) when she developed SCFE 3.3 years into GnRHa therapy. The third case was an 8.75-year-old female with CPP secondary to a hypothalamic hamartoma (BMI Z score +1.65) who developed bilateral SCFE 5.6 years into therapy., Conclusion: Increasing evidence suggests an association between GnRHa therapy for CPP and the occurrence of SCFE. We suggest that a lack of adequate sex hormone exposure at a 'critical period' of bone formation may result in a weakened epiphysis that becomes susceptible to slipping. © 2013 S. Karger AG, Basel.

Context: A broad spectrum of GnRH-deficient phenotypes has been identified in individuals with both mono- and biallelic GNRHR mutations., Objective: The objective of the study was to determine the correlation between the severity of the reproductive phenotype(s) and the number and functional severity of rare sequence variants in GNRHR., Subjects: Eight hundred sixty-three probands with different forms of GnRH deficiency, 46 family members and 422 controls were screened for GNRHR mutations. The 70 subjects (32 patients and 38 family members) harboring mutations were divided into four groups (G1-G4) based on the functional severity of the mutations (complete or partial loss of function) and the number of affected alleles (monoallelic or biallelic) with mutations, and these classes were mapped on their clinical phenotypes., Results: The prevalence of heterozygous rare sequence variants in GNRHR was significantly higher in probands vs. controls (P < 0.01). Among the G1-G3 groups (homozygous subjects with successively decreasing severity and number of mutations), the hypogonadotropic phenotype related to their genetic load. In contrast, subjects in G4, with only monoallelic mutations, demonstrated a greater diversity of clinical phenotypes., Conclusions: In patients with GnRH deficiency and biallelic mutations in GNRHR, genetic burden defined by severity and dose is associated with clinical phenotype. In contrast, for patients with monoallelic GNRHR mutations this correlation does not hold. Taken together, these data indicate that as-yet-unidentified genetic and/or environmental factors may combine with singly mutated GNRHR alleles to produce reproductive phenotypes.

Costimulation blockade is an effective way to prevent allograft rejection. In this study, we tested the efficacy of two negative co-signaling molecules in protecting islet allograft function. We used local expression of B7-H4 by adenoviral transduction of islets (Ad-B7-H4) and systemic administration of CTLA-4.Ig to investigate the outcomes of allograft survival. Five groups of streptozotocin-induced diabetic C57BL/6 mice received 400 islets each from BALB/c donors. The groups consisted of control (G1); CTLA-4.Ig (G2); Ad-LacZ (G3); Ad-B7-H4 (G4); and Ad-B7-H4 and CTLA-4.Ig combined (G5). G1 and G3 developed graft failure on average of two weeks. G2, G4 and G5 survived for 43.8 ± 34.8, 54.7 ± 31.2 and 77.8 ± 21.5 d, respectively. Activated T and B cells in the lymph nodes were significantly controlled by CTLA-4.Ig treatment. Significantly reduced infiltrates were also detected in the allografts of G2 compared with G1. By contrast, B7-H4 significantly inhibited Th1-associated IFN-gamma secretion in the early stage and increased Foxp3 (+) T cells in the long-term surviving allografts. Our study suggests that CTLA-4 and B7-H4 inhibit alloimmune responses through distinct mechanisms, and that combination therapy which activates two negative co-signaling pathways can further enhance islet allograft survival.

Negative cosignaling molecules play an important role in regulating T-cell responses to alloantigen stimulation. We recently reported that adenoviral-mediated transduction of islet allografts with B7-H4 inhibits allograft rejection. In this study, we investigate the mechanism for B7-H4-induced prolongation of mouse islet allograft survival. Streptozotocin-induced diabetic C57BL/6 mice were rendered normoglycemic by renal subcapsular implants of B7-H4-transduced BALB/c islets. Grafts and spleens were removed after days 2, 10, and 60 (n = 8 each) for characterization of kinetics of Foxp3 and interleukin 10 (IL-10) expression. Mixed lymphocyte reaction (MLR) was done at day 60. Ten mice were subjected to nephrectomy at 60 days and then five were implanted with secondary BALB/c islets and five were given third-party CBA/J islets. An increase in Foxp3 and IL-10 mRNA expression was detected in recipients' spleens at day 60 and this was associated with increased quantities of Foxp3(+) cells. Splenocytes at day 60 showed hyporesponsiveness during MLR to alloantigen stimulation. Proliferation was partially restored after CD25(+) T-cell depletion. Secondary BALB/c islets survived for 79 ± 29 days compared with 21 ± 3.6 days for CBA/J islets (p < 0.001). Local expression of B7-H4 induces long-term unresponsiveness to donor-specific alloantigens, and is associated with T regulatory cells, suggesting the development of tolerance.

Islet cell transplantation offers a potential cure for type 1 diabetes, but it is challenged by insufficient donor tissue and side effects of current immunosuppressive drugs. Therefore, alternative sources of insulin-producing cells and isletfriendly immunosuppression are required to increase the efficiency and safety of this procedure. Beta cells can be transdifferentiated from precursors or another heterologous (non-beta-cell) source. Recent advances in beta cell regeneration from somatic cells such as fibroblasts could circumvent the usage of immunosuppressive drugs. Therefore, generation of patient-specific beta cells provides the potential of an evolutionary treatment for patients with diabetes.

B7-H4 is a newly identified B7 homolog that plays an important role in maintaining T-cell homeostasis by inhibiting T-cell proliferation and lymphokine-secretion. In this study, we investigated the signal transduction pathways inhibited by B7-H4 engagement in mouse T cells. We found that treatment of CD3(+) T cells with a B7-H4.Ig fusion protein inhibits anti-CD3 elicited T-cell receptor (TCR)/CD28 signaling events, including phosphorylation of the MAP kinases, ERK, p38, and JNK. B7-H4.Ig treatment also inhibited the phosphorylation of AKT kinase and impaired its kinase activity as assessed by the phosphorylation of its endogenous substrate GSK-3. Expression of IL-2 is also reduced by B7-H4. In contrast, the phosphorylation state of the TCR proximal tyrosine kinases ZAP70 and lymphocyte-specific protein tyrosine kinase (LCK) are not affected by B7-H4 ligation. These results indicate that B7-H4 inhibits T-cell proliferation and IL-2 production through interfering with activation of ERK, JNK, and AKT, but not of ZAP70 or LCK.

Objective: Autoimmune diabetes is a T cell-mediated disease in which insulin-producing β-cells are destroyed. Autoreactive T cells play a central role in mediating β-cell destruction. B7-H4 is a negative cosignaling molecule that downregulates T-cell responses. In this study, we aim to determine the role of B7-H4 on regulation of β-cell-specific autoimmune responses., Research Design and Methods: Prediabetic (aged 3 weeks) female NOD mice (group 1, n = 21) were treated with intraperitoneal injections of B7-H4.Ig at 7.5 mg/kg, with the same amount of mouse IgG (group 2, n = 24), or with no protein injections (group 3, n = 24), every 3 days for 12 weeks., Results: B7-H4.Ig reduced the incidence of autoimmune diabetes, compared with the control groups (diabetic mice 28.6% of group 1, 66.7% of group 2 [P = 0.0081], and 70.8% of group 3 [group 1 vs. 3, P = 0.0035]). Histological analysis revealed that B7-H4 treatment did not block islet infiltration but rather suppressed further infiltrates after 9 weeks of treatment (group 1 vs. 2, P = 0.0003). B7-H4 treatment also reduced T-cell proliferation in response to GAD65 stimulation ex vivo. The reduction of diabetes is not due to inhibition of activated T cells in the periphery but rather to a transient increase of Foxp3(+) CD4(+) T-cell population at one week posttreatment (12.88 ± 1.29 vs. 11.58 ± 1.46%; n = 8; P = 0.03)., Conclusions: Our data demonstrate the protective role of B7-H4 in the development of autoimmune diabetes, suggesting a potential means of preventing type 1 diabetes by targeting the B7-H4 pathway.

We report the use of F-DOPA PET/CT imaging in the evaluation of a teenager with marked hypertension and right pararenal, left adrenal and left para-aortic mass lesions. The use of the modality for this clinical application has not been described previously within the pediatric imaging literature. The value of this technique relative to conventional imaging modalities is discussed and warrants consideration of its use, if available, for evaluating children with suspected paragangliomas/pheochromocytomas.

Type 1 diabetes (T1D) is a chronic autoimmune disease and characterized by absolute insulin deficiency. β-cell replacement by islet cell transplantation has been established as a feasible treatment option for T1D. The two main obstacles after islet transplantation are alloreactive T-cell-mediated graft rejection and recurrence of autoimmune diabetes mellitus in recipients. T cells play a central role in determining the outcome of both autoimmune responses and allograft survival. B7-H4, a newly identified B7 homolog, plays a key role in maintaining T-cell homeostasis by reducing T-cell proliferation and cytokine production. The relationship between B7-H4 and allograft survival/autoimmunity has been investigated recently in both islet transplantation and the nonobese diabetic (NOD) mouse models. B7-H4 protects allograft survival and generates donor-specific tolerance. It also prevents the development of autoimmune diabetes. More importantly, B7-H4 plays an indispensable role in alloimmunity in the absence of the classic CD28/CTLA-4 : B7 pathway, suggesting a synergistic/additive effect with other agents such as CTLA-4 on inhibition of unwanted immune responses.

Russell-Silver syndrome (RSS) is a heterogeneous disorder associated with pre- and post-natal growth restriction and relative macrocephaly. Involvement of imprinted genes on both chromosome 7 and 11p15.5 has been reported. To further characterize the role of epimutations in RSS we evaluated the methylation status at both 11p15.5 imprinting control regions (ICRs): ICR1 associated with H19/IGF2 expression and ICR2 (KvDMR1) associated with CDKN1C expression in a series of 35 patients with RSS. We also evaluated methylation at the promoter regions of other imprinted genes involved in growth such as PLAGL1 (6q24), GCE (7q21), and PEG10 (7q21) in this series of 35 patients with RSS. Thirteen of the 35 patient samples, but none of 22 controls, showed methylation levels at ICR1 that were more than 2 SD below the mean for controls. Three RSS patients were highly methylated at the SCGE promoter, all of which were diagnosed with upd(7)mat. To identify further potential global methylation changes in RSS patients, a subset of 22 patients were evaluated at 1505 CpG sites by the Illumina GoldenGate methylation array. Among the few CpG sites displaying a significant difference between RSS patients and controls, was a CpG associated with the H19 promoter. No other sites associated with known imprinted genes were identified as abnormally methylated in RSS patients by this approach. While the association of hypomethylation of the H19/IGF2 ICR1 is clear, the continuous distribution of methylation values among the patients and controls complicates the establishment of clear cut-offs for clinical diagnosis., (Copyright 2010 Wiley-Liss, Inc.)

Background: Allogeneic pancreatic islet transplantation has the potential to cure type 1 diabetes. One of the barriers to islet transplantation is the alloreactive T-cell response between donors and recipients. Costimulatory molecules, which play a major role in the regulation of the immune response to antigens during graft rejection, may be used to inhibit allograft destruction. B7-H4 is one such member in the costimulatory family, which has established negative regulatory function of T-cell responses., Methods: To determine whether local expression of B7-H4 protein can protect beta cells from damage in islet allotransplantation, we have constructed a recombinant adenovirus expressing a B7-H4 complementary deoxyribonucleic acid (Ad-B7-H4). To study the in vivo effects of B7-H4 expression on islet graft survival, adenovirus-transduced islets from donor Balb/c mice were transplanted into streptozotocin-diabetic C57BL/6 mice (n=12)., Results: Expression of B7-H4 in islets by Ad-B7-H4 transduction at an optimized condition did not inhibit glucose-stimulated insulin secretion of the treated islets. The recipient mice transplanted with Ad-B7-H4-transduced islets established euglycemia for a longer time (mean 56.5 days), compared with control mice transplanted with Ad-LacZ-transduced islets (mean 14.5 days, [n=12, P<0.001]). Splenocytes isolated from the recipients of Ad-B7-H4-transduced islets showed hyporesponsiveness to alloantigenic stimulation, compared with control recipients. CD45 and insulin staining of the graft transplanted with Ad-B7-H4-transduced islets indicated the preservation of beta cells and decrease of infiltrating immune cells., Conclusions: Local expression of B7-H4 prolongs islet allograft survival in vivo, suggesting translational potential for beta-cell replacement with reduced immune injury.

Premature ovarian failure (POF) is the occurrence of menopause before the age of 40, and may present with either primary or secondary amenorrhea. Numerous cases of POF in women with X-chromosome deletions or translocations have been reported; thus, it is possible that smaller rearrangements undetectable by conventional cytogenetics may contribute to POF in some patients. In females with an abnormal X chromosome, cells with inactivation of the normal X may be selected against, causing skewed X-chromosome inactivation (XCI). We therefore assessed XCI by methylation sensitive restriction digestion and PCR amplification at the androgen receptor (AR) locus, in 4 primary and 55 secondary POF patients and 109 control women. In samples heterozygous at AR and therefore informative for the skewing assay, the frequency of skewed XCI among the women with secondary amenorrhea was identical to that in control women, with 4 out of 48 (8.3%) secondary ovarian failure patients and 8 out of 97 (8.2%) control women having > or =90% skewing. Notably, all three primary amenorrhea patients that were informative at AR had skewed XCI > or =90% (P = 0.001 vs. control women; Fisher's exact test). To investigate whether X-chromosome copy number alterations were responsible, DNA from selected patients with skewed XCI was examined by high resolution DNA microarray, however no potential regions of DNA addition or deletion were confirmed by FISH or PCR. X-chromosome abnormalities undetectable by array, or reduced follicular pool due to an early trisomic rescue event, may explain the skewed XCI observed in POF patients presenting with primary amenorrhea.

B7-H4, a recently described member of the B7 family of cosignal molecules, is thought to be involved in the regulation of cellular and humoral immune responses through receptors on activated T and B cells. Human islet cells express positive B7-H4 mRNA in RT-PCR assays, but not B7-H4 protein on cell surface in flow cytometric analyses. To investigate the regulatory effects of activation of the B7-H4 pathway on the function of activated T cells of patients with type 1 diabetes (T1D), we have used our in vitro human experimental system, including human β-cell antigen-specific T-cell clones and human β-cell lines CM and HP62, as well as primary islet cells. B7-H4.Ig protein was purified from the culture supernatant of 293T cells transfected by a B7-H4.Ig plasmid (pMIgV, containing a human B7-H4 cDNA and a mouse IgG2a Fc cDNA). Our preliminary studies showed that immobilized fusion protein human B7-H4.Ig (coated with 5 μg/ml for 2 h at 37°C), but not control Ig, clearly inhibited the proliferation of activated CD4+ and CD8+ T cells of patients induced by anti-CD3 antibody in CFSE assays. B7-H4.Ig also arrested cell cycle progression of T cells in G 0 /G1 phase and induced T-cell apoptosis as measured by BrdU-7-AAD flow cytometric analysis. To determine the cytoprotective effects of B7-H4, we developed transfectants of human β-cell lines CM and HP62 and islet cells transfected with the B7-H4.Ig plasmid, using empty vector transfectants as controls. The results demonstrate that cell-associated B7-H4.Ig expressed on human β-cells clearly inhibits the cytotoxicity of the T-cell clones to targeted human β-cells in 51Cr release cytotoxicity assays. Activation of the B7-H4 pathway may represent a novel immunotherapeutic approach to inhibit T-cell responses for the prevention of β-cell destruction in T1D.

Mutations in KAL1 and FGFR1 cause Kallmann syndrome (KS), whereas mutations in the GNRHR and GPR54 genes cause idiopathic hypogonadotropic hypogonadism with normal olfaction (nIHH). Mixed pedigrees containing both KS and nIHH have also been described; however, the genetic cause of these rare cases is unknown. We examined the FGFR1 gene in seven nIHH subjects who either belonged to a mixed pedigree (n = 5) or who had associated midline defects (n = 2). Heterozygous FGFR1 mutations were found in three of seven unrelated nIHH probands with normal MRI of the olfactory system: (i) G237S in an nIHH female and a KS brother; (ii) (P722H and N724K) in an nIHH male missing two teeth and his mother with isolated hyposmia; and (iii) Q680X in a nIHH male with cleft lip/palate and missing teeth, his brother with nIHH, and his father with delayed puberty. We show that these mutations lead to receptor loss-of-function. The Q680X leads to an inactive FGFR1, which lacks a major portion of the tyrosine kinase domain (TKD). The G237S mutation inhibits proper folding of D2 of the FGFR1 and likely leads to the loss of cell-surface expression of FGFR1. In contrast, the (P722H and N724K) double mutation causes structural perturbations in TKD, reducing the catalytic activity of TKD. We conclude that loss-of-function mutations in FGFR1 cause nIHH with normal MRI of the olfactory system. These mutations also account for some of the mixed pedigrees, thus challenging the current idea that KS and nIHH are distinct entities.

B7-H4, a recently described member of the B7 family of cosignal molecules, is thought to be involved in the regulation of cellular and humoral immune responses through receptors on activated T and B cells. Human islet cells express positive B7-H4 mRNA in RT-PCR assays, but not B7-H4 protein on cell surface in flow cytometric analyses. To investigate the regulatory effects of activation of the B7-H4 pathway on the function of activated T cells of patients with type 1 diabetes (T1D), we have used our in vitro human experimental system, including human beta-cell antigen-specific T-cell clones and human beta-cell lines CM and HP62, as well as primary islet cells. B7-H4.Ig protein was purified from the culture supernatant of 293T cells transfected by a B7-H4.Ig plasmid (pMIgV, containing a human B7-H4 cDNA and a mouse IgG2a Fc cDNA). Our preliminary studies showed that immobilized fusion protein human B7-H4.Ig (coated with 5 microg/ml for 2 h at 37 degrees C), but not control Ig, clearly inhibited the proliferation of activated CD4+ and CD8+ T cells of patients induced by anti-CD3 antibody in CFSE assays. B7-H4.Ig also arrested cell cycle progression of T cells in G0/G1 phase and induced T-cell apoptosis as measured by BrdU-7-AAD flow cytometric analysis. To determine the cytoprotective effects of B7-H4, we developed transfectants of human beta-cell lines CM and HP62 and islet cells transfected with the B7-H4.Ig plasmid, using empty vector transfectants as controls. The results demonstrate that cell-associated B7-H4.Ig expressed on human beta-cells clearly inhibits the cytotoxicity of the T-cell clones to targeted human beta-cells in 51Cr release cytotoxicity assays. Activation of the B7-H4 pathway may represent a novel immunotherapeutic approach to inhibit T-cell responses for the prevention of beta-cell destruction in T1D.

Primary hypomagnesemia with secondary hypocalcemia is a rare autosomal recessive disorder characterized by profound hypomagnesemia associated with hypocalcemia. Pathophysiology is related to impaired intestinal absorption of magnesium accompanied by renal magnesium wasting as a result of a reabsorption defect in the distal convoluted tubule. Recently, mutations in the TRPM6 gene coding for TRPM6, a member of the transient receptor potential (TRP) family of cation channels, were identified as the underlying genetic defect. Here, the results of a TRPM6 mutational analysis of 21 families with 28 affected individuals are presented. In this large patient cohort, a retrospective clinical evaluation based on a standardized questionnaire was also performed. Genotype analysis revealed TRPM6 mutations in 37 of 42 expected mutant alleles. Sixteen new TRPM6 mutations were identified, including stop mutations, frame-shift mutations, splice-site mutations, and deletions of exons. Electrophysiologic analysis of mutated ion channels after heterologous expression in Xenopus oocytes proved complete loss of function of TRPM6. Clinical evaluation revealed a homogeneous clinical picture at manifestation with onset in early infancy with generalized cerebral convulsions. Initial laboratory evaluation yielded extremely low serum magnesium levels, low serum calcium levels, and inadequately low parathyroid hormone levels. Treatment usually consisted of acute intravenous magnesium supplementation leading to relief of clinical symptoms and normocalcemia, followed by lifelong oral magnesium supplementation. Serum magnesium levels remained in the subnormal range despite adequate therapy. This is best explained by a disturbed magnesium conservation in the distal convoluted tubule, which emerged in all patients upon magnesium supplementation. Delay of diagnosis resulted in permanent neurologic damage in three patients.

Context: Resistance to TSH (RTSH) is an inherited disorder of variable hyposensitivity to TSH. The metabolic consequences can range from euthyroid hyperthyrotropinemia to severe congenital hypothyroidism with thyroid hypoplasia. Although subclinical and mild hypothyroidism fitting the RTSH phenotype is common in the population, the role of genetic factors is far from being understood. Only in rare cases has RTSH been attributed to TSHR or PAX8 gene mutations. OBJECTIVE, SETTING, AND PARTICIPANTS: Toward the identification of novel RTSH genes, we studied five large, unrelated families comprising 102 individuals, 56 of whom were affected., Results: Inheritance of RTSH in these families followed an autosomal dominant pattern without evidence for incomplete penetrance, yet expressivity was variable. Considering only fully phenotyped generations, 64% of the progeny was affected, with a 1:1.4 male-to-female ratio. Of 18 affected individuals tested in the neonatal period, two were undetected because of borderline results. The thyroid phenotype was indistinguishable from that observed with PAX8 and TSHR defects. In four families, untreated affected subjects of all ages had elevated serum thyroglobulin levels, consistent with a defect in the thyroid follicle cells. Linkage of RTSH to TSHR and PAX8 was excluded in all five families. For the largest families, we likewise excluded a contribution of genes previously only associated with syndromic forms of RTSH, namely TITF1, GNAS, and FOXE1., Conclusions: These kindreds represent a distinct etiological entity of autosomal dominant RTSH. According to the clinical presentation of these families, genetic causes of mild hyperthyrotropinemia in the general population may be more common than currently appreciated.

Transfectants of human CM and NES2Y beta cell lines and primary islets transfected by FADD-DN (dominant-negative form of Fas-associated death domain), a mutant of FADD and/or a superrepressor of nuclear factor kappaB (NF-kappaB) (AdIkappaB(SA)2), were examined for their susceptibility to the TRAIL (TNF-related apoptosis-inducing ligand)-induced death signal pathway, compared with controls, wild-type cells, and vector transfectants in caspase fluorescence, Western blot, electrophoretic mobility shift, apoptosis, and cytotoxicity assays. FADD-DN inhibited caspase-8 activation induced by TRAIL in the transfectants of CM and NES2Y cells. TRAIL-induced apoptosis and cytotoxicity to the FADD-DN transfectants were decreased in comparison to those responses in controls (CM, p < 0.01 and p < 0.01; NES2Y, p < 0.05, and p < 0.02, respectively). When CM, NES2Y, and primary islet cells were transfected by AdIkappaB(SA)2, TRAIL-induced IkappaB degradation and nuclear translocation of NF-kappaB p50/p65 were blocked. TRAIL-induced apoptosis and cytotoxicity to AdIkappaB(SA)2 transfectants of these cells were also reduced (CM, p < 0.02 and p < 0.02; NES2Y, p < 0.01 and p < 0.01, respectively, and islet p < 0.01 for cytotoxicity). Finally, cytotoxicity induced by TRAIL in CM and NES2Y cells transfected with both FADD-DN and AdIkappaB(SA)2 was reduced, compared with that observed in these cells transfected with either FADD-DN alone or AdIkappaB(SA)2 alone, suggesting that FADD and NF-kappaB have synergistic proapoptotic regulatory effects on the susceptibility of beta cell lines and islet cells to TRAIL-induced destruction.

To better understand the cytokine death-signal transduction pathways in human beta cells, we investigated the inhibitory effects of Bcl-2 (protooncogene bcl-2) and X-linked inhibitor of apoptosis (XIAP) on TRAIL (TNF-related apoptosis-inducing ligand)-induced human beta-cell destruction. A panel of Bcl-2-overexpressing transfectants of the human beta-cell lines NES2Y and CM was developed by transfection with a pEFpGKpuro vector containing Bcl-2 or an empty vector as a control. TRAIL-induced cytotoxicity and apoptosis of Bcl-2-overexpressing beta cells were clearly decreased, in comparison with wild-type cells and the empty vector transfectants. XIAP-overexpressing CM, NES2Y, and primary islet cells were generated by exposing cells to recombinant adenovirus-expressing XIAP (AdXIAP) or AdLacz as a control. TRAIL-induced cytotoxicity and apoptosis of CM, NES2Y, and primary islet cells infected with AdXIAP were clearly reduced compared with controls. Interestingly, cytotoxicity induced by TRAIL in human beta cells transfected with both Bcl-2 and AdXIAP was much less than that observed in human beta cells transfected with either Bcl-2 or XIAP alone (p < 0.005 in CM and p < 0.03 in NES2Y). Overexpression of both Bcl-2 and XIAP inhibited TRAIL-induced activation of caspases as well as TRAIL-mediated damage of mitochondrial function in cells, suggesting possible regulatory mechanisms. These results indicate that Bcl-2 and XIAP synergistically inhibit TRAIL-mediated death pathways in human beta cells.

Objectives: Our previous report showed that beta-cell antigen-specific CD56+ T-cells and cytokine TRAIL mediate destruction of human pancreatic [beta] cells in vitro. To determine whether CD56 and TRAIL are present during islet cell destruction at the onset of clinical symptoms of type 1 diabetes mellitus (T1D), we studied cell marker and cytokine expression in the pancreatic islets of 2 children who died at presentation of acute-onset T1D and in T-cell lines derived from a group of children with new-onset T1D., Methods: TRAIL, CD56, and other T-cell markers and cytokine expression were studied using immunohistochemistry on pancreatic sections from 2 children with acute-onset T1D. TRAIL and CD56 expression was analyzed by flow cytometry in the antigen-activated T-cell lines derived from 29 children with new-onset T1D., Results: TRAIL+, CD56+, CD45RO+, and CD3+ cells were present in the islets of acute-onset T1D patients, while none were present in the normal islets. T-cell lines from new-onset T1D expressed TRAIL and CD56 in response to stimulation with beta-cell antigens GAD, IA-2 and insulin beta chain., Conclusion: The presence of TRAIL and CD56 markers is part of the T-cell response repertoire in beta-cell destruction.

Background: During the 2000-2001 season, an oculorespiratory syndrome (ORS) was identified in association with 1 manufacturer's influenza vaccine in Canada. ORS included bilateral red eyes, facial edema or respiratory symptoms beginning within 24 hours of influenza immunization. Few reports involved children. We assessed the rate of ORS in a pediatric cohort., Methods: In February 2001, invitation to participate in an influenza vaccine safety survey was sent to the parents of children who attend a diabetes clinic. A questionnaire elicited influenza immunization history and adverse event experience beginning within 1 day of vaccination for the child with diabetes and up to 3 siblings. Follow-up telephone interviews collected information from those who failed to return a questionnaire by mail., Results: Of the 959 households sent a questionnaire, 780 participated (81%). Among 780 children with diabetes, 418 (54%) received influenza vaccine in 2000. Adverse event experience was collected from an additional 242 immunized siblings. Among immunized children, 13% (95% confidence interval, 10-16%) experienced ORS, consisting primarily of respiratory symptoms. The majority (72%) resolved within 2 days. There was association between ORS and first time receipt of influenza vaccine (OR 2.7; 95% confidence interval, 1.6-4.4). Fewer parents of ORS-affected compared with unaffected children indicated that they were likely or very likely to have their child revaccinated (87 versus 97%; P < 0.001)., Conclusions: In 2000-2001, children experienced ORS in Canada at a rate comparable with that of adults. ORS should be incorporated into influenza vaccine safety monitoring and discussed with parents, especially those contemplating influenza vaccine for their child for the first time.