Growth and development of islet autoimmunity and type 1 diabetes in children genetically at risk.

AIMS/HYPOTHESIS: We aimed to evaluate the relationship between childhood growth measures and risk of developing islet autoimmunity (IA) and type 1 diabetes in children with an affected first-degree relative and increased HLA-conferred risk. We hypothesised that being overweight or obese during childhood is associated with a greater risk of IA and type 1 diabetes. METHODS: Participants in a randomised infant feeding trial (N = 2149) were measured at 12 month intervals for weight and length/height and followed for IA (at least one positive out of insulin autoantibodies, islet antigen-2 autoantibody, GAD autoantibody and zinc transporter 8 autoantibody) and development of type 1 diabetes from birth to 10-14 years. In this secondary analysis, Cox proportional hazard regression models were adjusted for birthweight and length z score, sex, HLA risk, maternal type 1 diabetes, mode of delivery and breastfeeding duration, and stratified by residence region (Australia, Canada, Northern Europe, Southern Europe, Central Europe and the USA). Longitudinal exposures were studied both by time-varying Cox proportional hazard regression and by joint modelling. Multiple testing was considered using family-wise error rate at 0.05. RESULTS: In the Trial to Reduce IDDM in the Genetically at Risk (TRIGR) population, 305 (14.2%) developed IA and 172 (8%) developed type 1 diabetes. The proportions of children overweight (including obese) and obese only were 28% and 9% at 10 years, respectively. Annual growth measures were not associated with IA, but being overweight at 2-10 years of life was associated with a twofold increase in the development of type 1 diabetes (HR 2.39; 95% CI 1.46, 3.92; p < 0.001 in time-varying Cox regression), and similarly with joint modelling. CONCLUSIONS/INTERPRETATION: In children at genetic risk of type 1 diabetes, being overweight at 2-10 years of age is associated with increased risk of progression from multiple IA to type 1 diabetes and with development of type 1 diabetes, but not with development of IA. Future studies should assess the impact of weight management strategies on these outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT00179777.

Sleep and quality of life of patients with glycogen storage disease on standard and modified uncooked cornstarch.

BACKGROUND: Glycemic control in hepatic glycogen storage diseases (GSDs) relies on specific nutritional recommendations, including strict avoidance of a fasting period. Uncooked cornstarch (UCCS) is an important therapeutic component. A new modified UCCS, Glycosade™, was created with the objective of prolonging euglycemia. We aimed to determine the length of euglycemia on Glycosade™ using a continuous glucose monitor (CGM) and to evaluate whether longer euglycemia and thus less nighttime interruptions would improve sleep and quality of life (QoL) after the introduction of the modified cornstarch. METHODS: We conducted a prospective cohort study to assess quality and quantity of sleep and quality of life (QoL) in patients with GSDs on standard UCCS and after the introduction of Glycosade™. Sleep and QoL evaluation was done for patients using validated questionnaires, a standardized sleep diary and actigraphy. Length of fast and glucose variability were determined with CGM. RESULTS: Nine adults with GSD Ia took part in the study. Glycosade™ introduction was done under close supervision during a hospital admission. Comparison of sleep in 9 patients showed sleep disturbances on standard UCCS that were improved with Glycosade™. QoL was normal both pre and post Glycosade™. The CGM confirmed maintenance of a longer fasting period with Glycosade™ at home. CONCLUSION: Glycosade™ represents an alternative option for GSD patients. We showed possible benefits in terms of sleep quality. We also confirmed the longer length of fast on Glycosade™. SYNOPSIS: A new modified form of uncooked starch for patients with glycogen storage disease represents an alternative option as it showed a longer length of fast and improvements in sleep quality.

Premature Ovarian Failure in French Canadian Leigh Syndrome.

In all surviving girls with Leigh syndrome, French Canadian variety, a mitochondrial disease, we detected premature ovarian failure, manifested as absent or arrested breast development, lack of menarche, high follicle-stimulating hormone, a prepubertal uterus, and small ovaries. Pubertal onset and progression should be evaluated in girls with mitochondrial diseases.

A search for variables predicting cortisol response to low-dose corticotropin stimulation following supraphysiological doses of glucocorticoids.

OBJECTIVES: To determine which biological or clinical variables may predict cortisol response to low-dose adrenocorticotropic hormone (ACTH) stimulation following supraphysiological doses of glucocorticoids in children. STUDY DESIGN: This retrospective study included all patients who underwent ACTH testing (1 µg) between October 2008 and June 2010 at the Sainte-Justine University Hospital Center, Montreal, after supraphysiological doses of glucocorticoids. RESULTS: Data from 103 patients (median age, 8.0 years; range, 0.6-18.5 years; 57 girls) were analyzed, revealing growth deceleration in 37% and excessive weight gain in 33%. Reasons for glucocorticoid treatment included asthma (n = 30) and hematologic (n = 22), dermatologic (n = 19), rheumatologic (n = 16), and miscellaneous (n = 16) disorders. The following information was recorded: duration of glucocorticoid treatment (median, 374 days; range, 5-4226 days); duration of physiological hydrocortisone replacement (median, 118 days; range, 0-1089 days); maximum daily (median, 200 mg/m(2)/day; range, 12-3750 mg/m(2)/day) and cumulative (median, 16 728 mg/m(2); range, 82-178 209 mg/m(2)) doses, in hydrocortisone equivalents; and interval since the last dose (median, 43 days; range, 1-1584 days). Sixty-two patients (58%) exhibited a normal response (ie, peak cortisol >500 nmol/L) to ACTH stimulation. Peak cortisol level was not related to sex, prior morning cortisol level, duration of treatment, or cumulative glucocorticoid dose; 28% of the patients with normal baseline cortisol levels nevertheless demonstrated a subnormal response to ACTH. CONCLUSION: Given the absence of clinical or biological predictors of the cortisol response to ACTH after suppressive doses of glucocorticoids, physicians have only 2 options: (1) empirically advocate glucocorticoid stress coverage during 18 months after cessation of high-dose glucocorticoid treatment; or (2) perform serial ACTH testing in all such patients until a normal peak cortisol level is attained.

Quality of referral of short children to the paediatric endocrinologist and impact of a fax communication system.

BACKGROUND/OBJECTIVES: In 2001, a chart review of children referred to the authors' endocrine clinic because of short stature revealed that many were referred with insufficient baseline data, had normal height velocity and were within genetic target height. Therefore, a two-way fax communication system was implemented between referring physicians and the authors' service before the first visit. Aspects that were assessed included whether this system increased the information accompanying the patient at referral, resulted in children with nonpathological shortness not being seen in the clinic, and was used differently by paediatricians and general practitioners. STUDY DESIGN: Between January and December 2006, 138 referrals for short stature, diagnosed with familial short stature, constitutional delay or idiopathic short stature, were audited (69 with and 69 without previous fax communication). Data collected included source of referral, clinical information provided, available growth measurements, and results from laboratory and imaging studies. RESULTS: Fax communication resulted in growth curves being provided more often (95.6% of cases versus 40.5% of cases without fax communication [P<0.001]) and more investigations being performed by the referring physician (median [range]: six [zero to 13] investigations versus one [zero to 11]; P<0.001), as well as a diagnosis of nonpathological short stature being given to 31 children based on the growth curve, laboratory and imaging results, without the children being seen in the endocrine clinic. Fax communication was also used more frequently by paediatricians (84%) than by general practitioners (15%). CONCLUSION: The fax communication system resulted in a more complete evaluation of referred patients by their physicians and reduced the number of unnecessary visits to the authors' specialty clinic while promoting medical education.

HISTORIQUE ET OBJECTIFS: En 2001, un examen des dossiers d'enfants aiguillés vers la clinique d'endocrinologie des auteurs en raison de leur petite taille a révélé que bon nombre des aiguillages ne s'accompagnaient pas de données de base suffisantes et que les patients aiguillés présentaient une croissance normale et une taille qui respectait leur cible génétique. C'est pourquoi un système de communication bidirectionnelle par télécopieur a été mis sur pied entre les médecins traitants et le service d'endocrinologie avant le premier rendez-vous. Les auteurs ont évalué si le système permettait d'avoir plus d'information au sujet du patient lors de l'aiguillage, s'il évitait que les patients dont la petite taille n'était pas d'origine pathologique soient vus à la clinique et s'il était utilisé de manière différente par les pédiatres et les omnipraticiens. MÉTHODOLOGIE: De janvier à décembre 2006, les auteurs ont évalué 138 aiguillages en raison d'une petite taille, diagnostiquée comme une petite taille familiale, un retard constitutionnel ou une petite taille idiopathique (69 avec et 69 sans communication antérieure par télécopieur). Les données colligées incluaient la source de l'aiguillage, l'information clinique fournie, les mesures de croissance transmises et les résultats des études de laboratoire et d'imagerie. RÉSULTATS: La communication par télécopieur a permis d'obtenir plus souvent les courbes de croissance (95,6 % des cas plutôt que 40,5 % [P<0,001]) et de faire faire plus d'examens par le médecin traitant (médiane [plage] : six [zéro à 13] examens au lieu d'un [zéro à 11]; P<0,001), ainsi que de poser un diagnostic de petite taille non pathologique chez 38 enfants d'après la courbe de croissance et les résultats de laboratoire et d'imagerie, sans qu'ils soient vus à la clinique d'endocrinologie. Par ailleurs, la communication par télécopieur était plus utilisée par les pédiatres (84 %) que par les omnipraticiens (15 %). CONCLUSION: Le système de communication par télécopieur a donné lieu à une évaluation plus complète des patients aiguillés par leur médecin et réduit le nombre de rendez-vous inutiles à la clinique spécialisée des auteurs, tout en favorisant la formation médicale.

Growth differences between North American and European children at risk for type 1 diabetes.

AIM: To evaluate the relationships between early growth and regional variations in type 1 diabetes (T1D) incidence in an international cohort of children with familial and genetic risk for T1D. METHODS: Anthropometric indices between birth to 5 yr of age were compared among regions and T1D proband in 2160 children participating in the Trial to Reduce Insulin-dependent diabetes mellitus in the Genetically at Risk study. RESULTS: Children in Northern Europe had the highest weight z-score between birth to 12 months of age, while those in Southern Europe and U.S.A. had the lowest weight and length/height z-scores at most time points (p < 0.005 to p < 0.001). Few differences in z-score values for weight, height, and body mass index were found by maternal T1D status. Using International Obesity Task Force criteria, the obesity rates generally increased with age and at 5 yr were highest in males in Northern Europe (6.0%) and in females in Canada (12.8%). However, no statistically significance difference was found by geographic region. In Canada, the obesity rate for female children of mothers with and without T1D differed significantly at 4 and 5 yr (6.0 vs. 0.0% and 21.3 vs. 1.9%, respectively; p < 0.0125) but no differences by maternal T1D status were found in other regions. CONCLUSIONS: There are regional differences in early childhood growth that are consistent with the higher incidence of T1D in Northern Europe and Canada as compared to Southern Europe. Our prospective study from birth will allow evaluation of relationships between growth and the emerging development of autoimmunity and progression to T1D by region in this at-risk population of children.

Residents as Research Subjects: Balancing Resident Education and Contribution to Advancing Educational Innovations.

Background: Research in education advances knowledge and improves learning, but the literature does not define how to protect residents' rights as subjects in studies or how to limit the impact of their participation on their clinical training. Objective: We aimed to develop a consensual framework on how to include residents as participants in education research, with the dual goal of protecting their rights and promoting their contributions to research. Methods: A nominal group technique approach was used to structure 3 iterative meetings held with the pre-existing residency training program committee and 7 invited experts between September 2018 and April 2019. Thematic text analysis was conducted to prepare a final report, including recommendations. Results: Five themes, each with recommendations, were identified: (1) Freedom of participation: participation, non-participation, or withdrawal from a study should not interfere with teacher-learner relationship (recommendation: improve recruitment and consent forms); (2) Avoidance of over-solicitation (recommendation: limit the number of ongoing studies); (3) Management of time dedicated to participation in research (recommendations: schedule and proportion of time for study participation); (4) Emotional safety (recommendation: requirement for debriefing and confidential counseling); and (5) Educational safety: data collected during a study should not influence clinical assessment of the resident (recommendation: principal investigator should not be involved in the evaluation process of learners in clinical rotation). Conclusions: Our nominal group technique approach resulted in raising 5 specific issues about freedom of participation of residents in research in medical education, over-solicitation, time dedicated to research, emotional safety, and educational safety.

Increasing Incidence of Type 1 and Type 2 Diabetes Among Canadian Children.

BACKGROUND: Diabetes mellitus is one of the most common pediatric chronic illnesses. Although a rising incidence of childhood type 1 diabetes (T1D) has frequently been documented, an almost 400-fold variation in incidence has been seen worldwide. We aimed to describe the trends in incidence of diabetes (type 1, type 2, all types) among children and adolescents living in the Greater Montréal area of Québec, Canada. METHODS: Using health administrative data (Québec Integrated Chronic Disease Surveillance System) and medical records from the 3 major pediatric diabetes centres in the Greater Montréal area, we conducted serial cross-sectional studies of children aged 1 to 15 years during the period from 2002 to 2010. We conducted a trend analysis of diabetes incidence over time using multivariate Poisson regression models. RESULTS: We identified 696 new cases of diabetes between 2002 and 2010. The age-standardized incidence of diabetes (all types) increased from 16.3 (95% confidence interval [CI], 12.4 to 21.2) to 27.8 (95% CI, 22.5 to 34.0) per 100,000, with annual incidence increasing, on average, by 5.2% per year (adjusted rate ratio [aRR], 1.052; 95% CI, 1.022 to 1.083). This was driven predominantly by the T1D annual increase of 5.4% (aRR, 1.054; 95% CI, 1.023 to 1.086). A low number of incident cases of type 2 diabetes limited trend analysis in this group. There were no significant interactions between year and sex or age. CONCLUSIONS: The annual incidence of T1D is increasing in Québec children and does not vary by sex or age. Further research into etiologic factors is indicated.

Decreased FGF8 signaling causes deficiency of gonadotropin-releasing hormone in humans and mice.

Idiopathic hypogonadotropic hypogonadism (IHH) with anosmia (Kallmann syndrome; KS) or with a normal sense of smell (normosmic IHH; nIHH) are heterogeneous genetic disorders associated with deficiency of gonadotropin-releasing hormone (GnRH). While loss-of-function mutations in FGF receptor 1 (FGFR1) cause human GnRH deficiency, to date no specific ligand for FGFR1 has been identified in GnRH neuron ontogeny. Using a candidate gene approach, we identified 6 missense mutations in FGF8 in IHH probands with variable olfactory phenotypes. These patients exhibited varied degrees of GnRH deficiency, including the rare adult-onset form of hypogonadotropic hypogonadism. Four mutations affected all 4 FGF8 splice isoforms (FGF8a, FGF8b, FGF8e, and FGF8f), while 2 mutations affected FGF8e and FGF8f isoforms only. The mutant FGF8b and FGF8f ligands exhibited decreased biological activity in vitro. Furthermore, mice homozygous for a hypomorphic Fgf8 allele lacked GnRH neurons in the hypothalamus, while heterozygous mice showed substantial decreases in the number of GnRH neurons and hypothalamic GnRH peptide concentration. In conclusion, we identified FGF8 as a gene implicated in GnRH deficiency in both humans and mice and demonstrated an exquisite sensitivity of GnRH neuron development to reductions in FGF8 signaling.

Simplifying Detection of Copy-Number Variations in Maturity-Onset Diabetes of the Young.

OBJECTIVES: Copy-number variations (CNVs) are large-scale deletions or duplications of DNA that have required specialized detection methods, such as microarray-based genomic hybridization or multiplex ligation probe amplification. However, recent advances in bioinformatics have made it possible to detect CNVs from next-generation DNA sequencing (NGS) data. Maturity-onset diabetes of the young (MODY) 5 is a subtype of autosomal-dominant diabetes that is often caused by heterozygous deletions involving the HNF1B gene on chromosome 17q12. We evaluated the utility of bioinformatic processing of raw NGS data to detect chromosome 17q12 deletions in MODY5 patients. METHODS: NGS data from 57 patients clinically suspected to have MODY but who were negative for pathogenic mutations using a targeted panel were re-examined using a CNV calling tool (CNV Caller, VarSeq version 1.4.3). Potential CNVs for MODY5 were then confirmed using whole-exome sequencing, cytogenetic analysis and breakpoint analysis when possible. RESULTS: Whole-gene deletions in HNF1B, ranging from 1.46 to 1.85 million basepairs in size, were detected in 3 individuals with features of MODY5. These were confirmed by independent methods to be part of a more extensive 17q12 deletion syndrome. Two additional patients carrying a 17q12 deletion were subsequently diagnosed using this method. CONCLUSIONS: Large-scale deletions are the most common cause of MODY5 and can be detected directly from NGS data, without the need for additional methods.

The effects of recreational cannabis use on glycemic outcomes and self-management behaviours in people with type 1 and type 2 diabetes: a rapid review.

BACKGROUND: Recent surveys of Canadian cannabis users reflect increasing consumption rates, some of whom may have diabetes. However, healthcare providers have limited information resources on the effects of recreational cannabis in people with diabetes. This rapid review was commissioned by Diabetes Canada to synthesize available evidence to guide recommendations for care of people 13 years of age and older who live with diabetes. METHODS: PubMed, Embase and PsycINFO databases were searched from January 2008 to January 2019. Study selection, data abstraction and quality appraisal were completed by pairs of reviewers working independently and discrepancies were resolved by a third reviewer with pilot tests completed before each stage to ensure consistency. Data collected from included studies were tabulated and summarized descriptively. RESULTS: The search resulted in 1848 citations of which 59 publications were selected for screening, resulting in six observational studies (2 full-text articles and 4 conference abstracts) that met the pre-defined criteria for inclusion. Five studies reported higher glycated hemoglobin (HbA1c) in people with type 1 diabetes (T1D) who consumed recreational cannabis. In one study, students aged 17 to 25 years living with T1D self-reported poorer glycemic control and higher HbA1c when smoking cannabis. In one study of adults with T1D, cannabis use within the previous 12 months was associated with almost double the risk of diabetic ketoacidosis compared with no cannabis use (odds ratio [OR] 1.98; confidence interval [CI] [95% CI] 1.01-3.91). Risks for peripheral arterial occlusion and myocardial infarction were found to be higher in people with type 2 diabetes (T2D) who consumed recreational cannabis, and worse renal parameters were also reported in two separate studies of T1D and T2D. CONCLUSIONS: Recreational cannabis use may negatively impact diabetes metabolic factors and self-management behaviours in people with T1D. In people with T2D, recreational cannabis may increase risks for peripheral arterial occlusion, myocardial infarction and renal disease. However, the evidence base of this rapid review was limited to six observational studies of poor to fair methodological quality, and thus, further robust, higher quality research is required to confirm the potential impact of cannabis on diabetes. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42019122829.

Comparison of adolescents with Klinefelter syndrome according to the circumstances of diagnosis: amniocentesis versus clinical signs.

AIMS: We compared the phenotype of adolescents with Klinefelter syndrome diagnosed by amniocentesis or postnatally to the general population with a view to evidence-based genetic counselling. METHODS: The charts of 28 patients seen between ages 12 and 18 years were reviewed. Physical and neurodevelopmental data were compared between patients diagnosed by chance (amniocentesis, group A, n = 11) or on the basis of symptoms (group B, n = 17) and the general population. Our hypothesis was that group A would have a more heterogeneous and less severe phenotype than group B. RESULTS: All patients had spontaneous puberty. The 2 patient groups were similar in physical development. Mean testosteronemia became lower than the normal mean from age 14 years. Compared to the general population, the prevalence of gynecomastia and school delay in group A was not significantly different (gynecomastia 33 vs. 40%, p = 0.70; school delay 40 vs. 20%, p = 0.25). In contrast, gynecomastia (77%) and school delay (56%) were significantly more frequent in group B than in the general population (p = 0.01 for both). CONCLUSIONS: Although they are based on a small number of patients, our data provide the groundwork for cautious optimism in prenatal counselling for Klinefelter syndrome.

Outcome after bariatric surgery in two adolescents with hypothalamic obesity following treatment of craniopharyngioma.

Treatment of craniopharyngioma (CP) in childhood can lead to severe, debilitating obesity with devastating medical and psychological outcomes. Despite sustained nutritional and exercise-oriented interventions, no efficacious medical option is available for hypothalamic obesity. We describe two adolescents who developed morbid obesity and significant comorbidities following diagnosis and treatment of CP, in whom bariatric surgery was achieved, illustrating a novel approach for symptomatic hypothalamic obesity, as well as positive and negative outcomes.

Copy Number Variation in GCK in Patients With Maturity-Onset Diabetes of the Young.

PURPOSE: Next generation sequencing (NGS) methods to diagnose maturity-onset diabetes of the young (MODY), a monogenic autosomal dominant cause of diabetes, do not typically detect large-scale copy number variations (CNVs). New techniques may allow assessment for CNVs using output data from targeted NGS, without requiring additional sequencing. Using this technique, two kindreds of patients presenting with features of MODY were found to bear the same heterozygous large-scale deletion in GCK. METHODS: Patients suspected of having MODY but with negative targeted NGS pathogenic variant calling were reanalyzed using the CNV caller tool (VarSeq v1.4.3). Two patients were identified as having a possible heterozygous whole exon deletion affecting exon 1 of GCK. For confirmation and determination of the exact breakpoints, whole exome sequencing followed by Sanger sequencing were used. Familial samples from both affected and nonaffected first-degree relatives were then analyzed for each proband. RESULTS: A heterozygous whole-exon deletion spanning 4763 bp affecting the entire exon 1 of GCK was detected in two apparently unrelated patients with clinical features of MODY. This deletion showed segregation concordance across generations in affected and nonaffected family members. CONCLUSIONS: Our findings confirm the utility of applying the CNV caller tool to screen for CNVs in GCK from NGS data. In so doing, we identified a deletion of exon 1 of GCK as likely causal for MODY. Our data indicate that incorporating CNV analysis routinely when assessing for MODY via targeted NGS may increase diagnostic yield and reduce false negative genetic testing rates.

Diabetes Canada Position Statement on Recreational Cannabis Use in Adults and Adolescents With Type 1 and Type 2 Diabetes.

OBJECTIVE: Pursuant to the legalization of recreational cannabis in Canada, a rapid review was undertaken to develop a position statement concerning the effects of cannabis consumption on Canadians living with diabetes. METHODS: An expert committee of 1 adult endocrinologist and 1 pediatric endocrinologist, with the help of coauthors, collaborated to develop the position statement using the same evidence-based principles as the Diabetes Canada Clinical Practice Guidelines (with the exception of an independent methods review). A rapid review was conducted by researchers with the Strategic Patient-Oriented Research Evidence Alliance. The scope of the review was limited to evaluating the effects of recreational cannabis use on: 1) metabolic factors and diabetes complications, and 2) diabetes self-management behaviors in people ≥13 years of age. An informed person with diabetes, Canadian health-care providers and scientific advisors performed independent external reviews. RESULTS: The review found a limited amount of published or presented literature for the review questions, with gaps in direct evidence linking cessation of cannabis use to improved outcomes in diabetes. However, there were sufficient data to begin developing recommendations for type 1 and type 2 diabetes about education, counseling and management related to recreational cannabis usage. CONCLUSIONS: This is the first attempt in the world to generate an evidence-based guidance document on the topic of recreational cannabis use and diabetes. It provides guidance for health-care providers, so that they can assist and counsel Canadians living with diabetes on recreational cannabis. Further, higher quality research is required to provide more robust and evidence-informed guidance.

Adrenal suppression from glucocorticoids: preventing an iatrogenic cause of morbidity and mortality in children.

Adrenal suppression (AS) is an important side effect of glucocorticoids (GCs) including inhaled corticosteroids (ICS). AS can often be asymptomatic or associated with non-specific symptoms until a physiological stress such as an illness precipitates an adrenal crisis. Morbidity and death associated with adrenal crisis is preventable but continues to be reported in children. There is a lack of consensus about the management of children at risk of AS. However, healthcare professionals need to develop an awareness and approach to keep these children safe. In this article, current knowledge of the risk factors, diagnosis and management of AS are reviewed while drawing attention to knowledge gaps and areas of controversy. Possible strategies to reduce the morbidity associated with this iatrogenic condition are provided for healthcare professionals.

Identifying pediatric diabetes cases from health administrative data: a population-based validation study in Quebec, Canada.

BACKGROUND: Type 1 diabetes is one of the most common chronic diseases in childhood with a worldwide incidence that is increasing by 3-5% per year. The incidence of type 2 diabetes, traditionally viewed as an adult disease, is increasing at alarming rates in children, paralleling the rise in childhood obesity. As the rates of diabetes increase in children, accurate population-based assessment of disease burden is important for those implementing strategies for health services delivery. Health administrative data are a powerful tool that can be used to track disease burden, health services use, and health outcomes. Case validation is essential in ensuring accurate disease identification using administrative databases. AIM: The aim of our study was to define and validate a pediatric diabetes case ascertainment algorithm (including any form of childhood-onset diabetes) using health administrative data. RESEARCH DESIGN AND METHODS: We conducted a two-stage method using linked health administrative data and data extracted from charts. In stage 1, we linked chart data from a large urban region to health administrative data and compared the diagnostic accuracy of various algorithms. We selected those that performed the best to be validated in stage 2. In stage 2, the most accurate algorithms were validated with chart data within two other geographic areas in the province of Quebec. RESULTS: Accurate identification of diabetes in children (ages ≤15 years) required four physician claims or one hospitalization (with International Classification of Disease codes within 1 year (sensitivity 91.2%, 95% confidence interval [CI] 89.2-92.9]; positive predictive value [PPV] 93.5%, 95% CI 91.7-95.0) or using only four physician claims in 2 years (sensitivity 90.4%, 95% CI 88.3-92.2; PPV 93.2%, 95% CI 91.7-95.0). Separating the physician claims by 30 days increased the PPV of all algorithms tested. CONCLUSION: Patients with child-onset diabetes can be accurately identified within health administrative databases providing a valid source of information for health care resource planning and evaluation.

Mutations in prokineticin 2 and prokineticin receptor 2 genes in human gonadotrophin-releasing hormone deficiency: molecular genetics and clinical spectrum.

CONTEXT: Mice deficient in prokineticin 2(PROK2) and prokineticin receptor2 (PROKR2) exhibit variable olfactory bulb dysgenesis and GnRH neuronal migration defects reminiscent of human GnRH deficiency. OBJECTIVES: We aimed to screen a large cohort of patients with Kallmann syndrome (KS) and normosmic idiopathic hypogonadotropic hypogonadism (IHH) for mutations in PROK2/PROKR2, evaluate their prevalence, define the genotype/phenotype relationship, and assess the functionality of these mutant alleles in vitro. DESIGN: Sequencing of the PROK2 and PROKR2 genes was performed in 170 KS patients and 154 nIHH. Mutations were examined using early growth response 1-luciferase assays in HEK 293 cells and aequorin assays in Chinese hamster ovary cells. RESULTS: Four heterozygous and one homozygous PROK2 mutation (p.A24P, p.C34Y, p.I50M, p.R73C, and p.I55fsX1) were identified in five probands. Four probands had KS and one nIHH, and all had absent puberty. Each mutant peptide impaired receptor signaling in vitro except the I50M. There were 11 patients who carried a heterozygous PROKR2 mutation (p.R85C, p.Y113H, p.V115M, p.R164Q, p.L173R, p.W178S, p.S188L, p.R248Q, p.V331M, and p.R357W). Among them, six had KS, four nIHH, and one KS proband carried both a PROKR2 (p.V115M) and PROK2 (p.A24P) mutation. Reproductive phenotypes ranged from absent to partial puberty to complete reversal of GnRH deficiency after discontinuation of therapy. All mutant alleles appear to decrease intracellular calcium mobilization; seven exhibited decreased MAPK signaling, and six displayed decreased receptor expression. Nonreproductive phenotypes included fibrous dysplasia, sleep disorder, synkinesia, and epilepsy. Finally, considerable variability was evident in family members with the same mutation, including asymptomatic carriers. CONCLUSION: Loss-of-function mutations in PROK2 and PROKR2 underlie both KS and nIHH.