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.

Is ultrasonography useful in predicting thyroid cancer in children with thyroid nodules and apparently benign cytopathologic features?

BACKGROUND/AIMS: To assess whether the presence of certain findings on thyroid ultrasonography (US) correctly diagnoses malignancy even when a fine-needle aspiration biopsy (FNAB) suggests a benign lesion. METHODS: We reviewed the charts of 35 children and adolescents with a thyroid nodule who had had an US and a FNAB, and for whom final pathology was available. RESULTS: The global accuracy of FNAB was 83%, with a sensitivity of 75% and a specificity of 94%. 14 FNABs suggested malignancy (40%), only 1 of which was a false positive (7%). By contrast, 5 of the 21 FNABs suggesting benign lesions were false negatives (24%). These 5 cases had US findings suggestive of malignancy. When FNAB suggested a benign lesion, US had a good sensitivity (80%) but a poor specificity and accuracy (50 and 57%, respectively); its negative predictive value was 90% and its positive predictive value 36%. CONCLUSIONS: US complements FNAB in the evaluation of thyroid nodules in children. A more aggressive approach is warranted in children with a thyroid nodule and a benign FNAB if US findings suggest malignancy.

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.

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.

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.

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.

Circulating IL-6 concentrations and abdominal adipocyte isoproterenol-stimulated lipolysis in women.

OBJECTIVE: To examine the association of plasma interleukin-6 (IL-6) concentrations with adiposity and fat cell metabolism in women. METHODS AND PROCEDURES: Omental (OM) and subcutaneous (SC) adipose tissue samples were obtained from 48 healthy women (age: 47+/-5 years, BMI: 26.9+/-5.3 kg/m(2)) undergoing gynecological surgeries. Total and visceral adiposity were assessed by dual-energy X-ray absorptiometry and computed tomography, respectively. Measures of adipocyte lipolysis (basal, isoproterenol-, forskolin-, and cyclic dibutyryl-adenosine monophosphate (AMP)-stimulated) and adipose tissue lipoprotein lipase (LPL) activity were obtained. Plasma IL-6 was measured by radioimmunoassay. RESULTS: Plasma IL-6 was positively correlated with total body fat mass (r=0.32, P<0.05), SC adipose tissue area (r=0.35, P<0.05), SC adipocyte diameter (r=0.30, P<0.05), and a trend was observed with visceral adipose tissue area (r=0.20, P<0.07). Plasma IL-6 was positively correlated with glycerol released in response to isoproterenol (10(-5) to 10(-8) mol/l) by isolated SC (0.31

Oxidative stress and cystic fibrosis-related diabetes: a pilot study in children.

BACKGROUND: Cystic fibrosis (CF) is characterized by chronic inflammation with increased oxidative stress. We evaluated the relationship between glucose tolerance and oxidative stress in CF children. METHODS: Patients 10-18 years old underwent oral glucose tolerance testing (n=31). At 2-h, we assessed blood glutathione and 4-hydroxynonenal-protein adducts (HNE-P), and urine 1,4-dihydroxynonane-mercapturic acid conjugate (DHN-MA). Plasma fatty acid (FA) profile was performed. Patients with impaired glucose tolerance (IGT) were retested 6 to 24 months later and received additional nutritional recommendations (NR) when possible. RESULTS: Fifty-two percent of patients had normal glucose tolerance (NGT), 42% IGT and 6% cystic fibrosis-related diabetes (CFRD). HNE-P concentrations significantly increased with diabetes (109%). Two-h BG correlated positively with HNE-P and negatively with DHN-MA. FA profile was modified with IGT. Of retested IGT patients, 25% received no NR; they remained IGT at 6 months and progressed to CFRD. Of those who received NR, 67% normalized, 11% remained intolerant and 22% developed CFRD. HNE-P levels dropped (88%) in IGT patients reverting to NGT, increased (94%) in the IGT patients with NR developing CFRD, decreased (90%) with persistent IGT. CONCLUSION: CF children showed evidence of increased oxidative stress with worsening of glucose metabolism. NR may delay the appearance of CFRD.

Cumulative doses of adjunct 131I treatment depend on location of residual thyroid tissue after total thyroidectomy in differentiated thyroid cancer.

PURPOSE: The aim of this study was to review the outcome after adjunct postoperative 131I therapy in patients with differentiated thyroid carcinoma (DTC) treated with total thyroidectomy (excluding medullary thyroid carcinoma). METHODS: Retrospective chart review: Management protocol is total thyroidectomy with cervical node sampling, 131I whole-body scan 3 weeks postoperatively to document residual thyroid tissue or metastatic lesions. Adjunct treatment consists of one or more 131I (100-200 mci/1.73 m2). Patients are considered disease free if 2 consecutive 131I whole-body scan are negative with undetectable thyroglobulin level. RESULTS: Twenty-one patients, 14 females and 7 males, with a mean age of 13.6 years were treated. Whole-body scan postoperatively revealed uptake in the thyroid bed (TB) in 10 patients, in cervical lymph nodes (CLN) in 9 patients, and in CLN and lungs in 2 patients. Patients with residual uptake in TB received a significantly lesser dose of 131I (mean, 122 +/- 53 mci) than those with metastatic CLN (357 +/- 182 mci) (P < .004) (t test) or lung mets (523.5 mci). With a mean follow-up of 7.8 years (range, 1-16 years), overall survival is 100% but disease-free survival is 100%, 66%, and 0% respectively for patients with residual disease in TB, CLN, and lungs. CONCLUSION: Patient with residual thyroid tissue in the TB required a significantly lesser number of treatments and doses of 131I compared to patients with cervical node metastases with a 100% disease-free survival. The best management of immediate postoperative residual cervical nodes (surgical excision vs 131I) remains to be defined. The efficacy of 131I therapy in patients with lung metastases remains controversial with complete remission unlikely.

Primary adrenal insufficiency in children: twenty years experience at the Sainte-Justine Hospital, Montreal.

Primary adrenal insufficiency (PAI) in the pediatric population (0-18 yr) is most commonly attributed to congenital adrenal hyperplasia (CAH), which occurs in about 1 in 15,000 births, followed by Addison's disease, with an assumed autoimmune etiology. However, molecular advances have increased the number of possible diagnoses. The objective of this study was to determine the incidence and etiologies of PAI in our pediatric population. All patients with a diagnosis of PAI followed by the Endocrinology Service at our institution between September 1981 and September 2001 were studied. One hundred three patients (48 boys) were identified, primarily by the Endocrinology Clinic case registry. CAH was the most frequent etiology (71.8%). However, non-CAH etiologies accounted for 28.2%, of which 55% were nonautoimmune in etiology. Importantly, the CAH sex ratio was 1:1, despite the absence of biochemical screening for this condition in Quebec newborns. Patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dysplasia (APECED) developed adrenal insufficiency 4 yr earlier than those with non-autoimmune disease. Finally, we review the rare etiologies of PAI and propose an algorithm to aid in targeted genetic testing.