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BACKGROUND: Gender clinic and single-item questionnaire-based data report increased co-occurrence of gender diversity and neurodevelopmental conditions. The nuances of these associations are under-studied. We used a transdiagnostic approach, combining categorical and dimensional characterization of neurodiversity, to further the understanding of its associations with gender diversity in identity and expression in children. METHODS: Data from 291 children (Autism N = 104, ADHD N = 104, Autism + ADHD N = 17, neurotypical N = 66) aged 4-12 years enrolled in the Province of Ontario Neurodevelopmental Network were analyzed. Gender diversity was measured multi-dimensionally using a well-validated parent-report instrument, the Gender Identity Questionnaire for Children (GIQC). We used gamma regression models to determine the significant correlates of gender diversity among age, puberty, sex-assigned-at-birth, categorical neurodevelopmental diagnoses, and dimensional neurodivergent traits (using the Social Communication Questionnaire and the Strengths and Weaknesses of ADHD Symptoms and Normal Behavior Rating Scales). Internalizing and externalizing problems were included as covariates. RESULTS: Neither a categorical diagnosis of autism nor ADHD significantly correlated with current GIQC-derived scores. Instead, higher early-childhood dimensional autistic social-communication traits correlated with higher current overall gender incongruence (as defined by GIQC-14 score). This correlation was potentially moderated by sex-assigned-at-birth: greater early-childhood autistic social-communication traits were associated with higher current overall gender incongruence in assigned-males-at-birth, but not assigned-females-at-birth. For fine-grained gender diversity domains, greater autistic restricted-repetitive behavior traits were associated with greater diversity in gender identity across sexes-assigned-at-birth; greater autistic social-communication traits were associated with lower stereotypical male expression across sexes-assigned-at-birth. CONCLUSIONS: Dimensional autistic traits, rather than ADHD traits or categorical neurodevelopmental diagnoses, were associated with gender diversity domains across neurodivergent and neurotypical children. The association between early-childhood autistic social-communication traits and overall current gender diversity was most evident in assigned-males-at-birth. Nuanced interrelationships between neurodivergence and gender diversity should be better understood to clarify developmental links and to offer tailored support for neurodivergent and gender-diverse populations.
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Transtorno do Deficit de Atenção com Hiperatividade , Humanos , Masculino , Feminino , Pré-Escolar , Criança , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Transtorno do Espectro Autista/fisiopatologia , Transtorno Autístico/fisiopatologia , Identidade de Gênero , Transtornos do Neurodesenvolvimento/epidemiologiaRESUMO
Extensive evidence supports the role of the immune system in modulating brain function and behaviour. However, past studies have revealed striking heterogeneity in behavioural phenotypes produced from immune system dysfunction. Using magnetic resonance imaging, we studied the neuroanatomical differences among 11 distinct genetically modified mouse lines (n = 371), each deficient in a different element of the immune system. We found a significant and heterogeneous effect of immune dysfunction on the brains of both male and female mice. However, by imaging the whole brain and using Bayesian hierarchical modelling, we were able to identify patterns within the heterogeneous phenotype. Certain structures-such as the corpus callosum, midbrain, and thalamus-were more likely to be affected by immune dysfunction. A notable brain-behaviour relationship was identified with neuroanatomy endophenotypes across mouse models clustering according to anxiety-like behaviour phenotypes reported in literature, such as altered volume in brains regions associated with promoting fear response (e.g., the lateral septum and cerebellum). Interestingly, genes with preferential spatial expression in the most commonly affected regions are also associated with multiple sclerosis and other immune-mediated diseases. In total, our data suggest that the immune system modulates anxiety behaviour through well-established brain networks.
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Encéfalo , Neuroanatomia , Animais , Ansiedade , Teorema de Bayes , Encéfalo/metabolismo , Modelos Animais de Doenças , Feminino , Imageamento por Ressonância Magnética , Masculino , Camundongos , FenótipoRESUMO
BACKGROUND: The pan-Canadian Maternal-Infant Research on Environmental Chemicals (MIREC) study was established to determine whether maternal environmental chemical exposures were associated with adverse pregnancy outcomes in 2001 pregnant women. OBJECTIVES: The MIREC-Child Development (CD PLUS) study followed this cohort with the goal of assessing the potential effects of prenatal exposures on anthropometry and neurodevelopment in early childhood. POPULATION: MIREC families with children between the ages of 15 months and 5 years who had agreed to be contacted for future research (n = 1459) were invited to participate in MIREC-CD PLUS which combines data collected from an online Maternal Self-Administered Questionnaire with biomonitoring and neurodevelopment data collected from two in-person visits. PRELIMINARY RESULTS: Between April 2013 and March 2015, 803 children participated in the Biomonitoring visit where we collected anthropometric measures, blood, and urine from the children. The Behavioural Assessment System for Children-2, Behaviour Rating Inventory of Executive Function, MacArthur-Bates Communicative Development Inventories and the Communication subscale of the Adaptive Behaviour Scale from the Bayley Scales of Infant and Toddler Development-III are available on close to 900 children. There were 610 singleton children who completed in-person visits for neurodevelopment assessments including the Social Responsiveness Scale, Wechsler Preschool Primary Scale of Intelligence-III and NEuroPSYchological assessments (NEPSY). Currently, we are following the cohort into early adolescence to measure the impact of early life exposures on endocrine and metabolic function (MIREC-ENDO). CONCLUSIONS: Data collection for the MIREC-CD PLUS study is complete and analysis of the data continues. We are now extending the follow-up of the cohort into adolescence to measure the impact of early life exposures on endocrine and metabolic function (MIREC-ENDO). MIREC-CD PLUS is limited by loss to follow-up and the fact that mothers are predominately of higher socioeconomic status and 'White' ethnicity, which limits our generalizability. However, the depth of biomonitoring and clinical measures in MIREC provides a platform to examine associations of prenatal, infancy and childhood exposures with child growth and development.
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Desenvolvimento Infantil , Efeitos Tardios da Exposição Pré-Natal , Adolescente , Humanos , Gravidez , Lactente , Feminino , Pré-Escolar , Canadá/epidemiologia , Exposição Ambiental/efeitos adversos , Exposição Materna/efeitos adversos , Resultado da Gravidez , Efeitos Tardios da Exposição Pré-Natal/epidemiologiaRESUMO
OBJECTIVES: To promote resource stewardship in thyroid hormone testing at a pediatric tertiary care hospital. STUDY DESIGN: Quality improvement approaches generated 3 change ideas that were implemented simultaneously in the hospital electronic medical record: (1) a reflex free thyroxine (fT4), whereby fT4 is automatically reported if the thyroid-stimulating hormone is outside the normal range; (2) a forced-function for thyroid hormone ordering, whereby a provider must select an appropriate indication for ordering fT4 or triiodothyronine (T3); and (3) a clinical decision support message displayed at the time of ordering thyroid function tests. Laboratory data were audited to determine the mean number of fT4 and T3 tests performed per week as well as indications for testing. RESULTS: The mean number of fT4 and T3 tests processed per week decreased from 154 ± 21 and 11 ± 7, respectively, in the preintervention period, to 107 ± 12 (30% reduction) and 4 ± 3 (66% reduction) postintervention. These reductions were sustained for the full 20-week assessment period. Process and balancing measures revealed no unintended adverse consequences. Approximate cost savings were $43 000 per year. CONCLUSIONS: We describe the successful implementation of electronic medical record-based interventions (reflex fT4, forced-function selection of indication, decision support text) leading to sustained improvements in healthcare use, with significant associated cost-savings.
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Sistemas de Apoio a Decisões Clínicas , Melhoria de Qualidade , Testes de Função Tireóidea , Procedimentos Desnecessários , Canadá , Redução de Custos , Registros Eletrônicos de Saúde , Humanos , Centros de Atenção Terciária , Testes de Função Tireóidea/economiaRESUMO
The timing of human puberty is highly variable, sexually dimorphic, and associated with adverse health outcomes. Over 20 genes carrying rare mutations have been identified in known pubertal disorders, many of which encode critical components of the hypothalamic-pituitary-gonadal (HPG) axis. Recent genome-wide association studies (GWAS) have identified more than 100 candidate genes at loci associated with age at menarche or voice breaking in males. We know little about the spatial, temporal or postnatal expression patterns of the majority of these puberty-associated genes. Using a high-throughput and sensitive microfluidic quantitative PCR strategy, we profiled the gene expression patterns of the mouse orthologs of 178 puberty-associated genes in male and female mouse HPG axis tissues, the pineal gland, and the liver at five postnatal ages spanning the pubertal transition. The most dynamic gene expression changes were observed prior to puberty in all tissues. We detected known and novel tissue-enhanced gene expression patterns, with the hypothalamus expressing the largest number of the puberty-associated genes. Notably, over 40 puberty-associated genes in the pituitary gland showed sex-biased gene expression, most of which occurred peri-puberty. These sex-biased genes included the orthologs of candidate genes at GWAS loci that show sex-discordant effects on pubertal timing. Our findings provide new insight into the expression of puberty-associated genes and support the possibility that the pituitary plays a role in determining sex differences in the timing of puberty.
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Maturidade Sexual/genética , Transcriptoma/genética , Animais , Feminino , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Estudo de Associação Genômica Ampla/métodos , Sistema Hipotálamo-Hipofisário , Hipotálamo/metabolismo , Masculino , Camundongos , Análise em Microsséries , Hipófise/metabolismo , Sistema Hipófise-Suprarrenal , Caracteres Sexuais , Fatores SexuaisRESUMO
BACKGROUND: When young adults transfer from pediatric to adult diabetes care they are at risk for deterioration of glycemic control, putting them at an increased risk of developing both acute and chronic complications. Despite increased awareness of these risks, there are gaps in care delivery during this vulnerable time and variability in the implementation of recommended transition practice. Audit and feedback (AF) interventions have a positive but variable effect on implementation of best practices. An expert group identified specific suggestions for optimizing the effectiveness of AF interventions. We aim to test an AF-based intervention incorporating these specific suggestions to improve transition practices and glycemic control in the first year after transfer from pediatric to adult diabetes care. METHODS: This is a pragmatic quasi-experimental study; a series of three cohort studies (pre-implementation, early-implementation, and post-implementation) to compare the baseline adjusted hemoglobin A1c (HbA1c) in the 12 months after the final pediatric visit in five pediatric diabetes centres within the Ontario Pediatric Diabetes Network in Ontario, Canada. The intervention includes three components: 1) centre-level feedback reports compiling data from chart abstraction, linked provincial administrative datasets, and patient-reported experience measures; 2) webinars for facilitated conversations/coaching about the feedback; and 3) online repository of curated transition resources for providers. The primary outcome will be analyzed using a multivariable linear regression model. We will conduct a qualitative process evaluation to understand intervention fidelity and to provide insight into the mechanisms of action of our results. DISCUSSION: There is a need to develop an innovative system-level approach to improve outcomes and the quality of care for young adults with type 1 diabetes during the vulnerable time when they transfer to adult care. Our research team, a collaboration of health services, implementation science, and quality improvement researchers, are designing, implementing, and evaluating an AF-based intervention using recommendations about how to optimize effectiveness. This knowledge will be generalizable to other care networks that aim to deliver uniformly high-quality care in diverse care settings. TRIAL REGISTRATION: ClinicalTrials.gov NCT03781973. Registered 13 December 2018. Date of enrolment of the first participant to the trial: June 1, 2019.
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Glicemia/metabolismo , Diabetes Mellitus Tipo 1/terapia , Melhoria de Qualidade , Transição para Assistência do Adulto/organização & administração , Adolescente , Retroalimentação , Pesquisa sobre Serviços de Saúde , Humanos , Auditoria Médica , Ontário , Projetos de Pesquisa , Adulto JovemRESUMO
IN BRIEF "Quality Improvement Success Stories" are published by the American Diabetes Association in collaboration with the American College of Physicians, Inc. (ACP), and the National Diabetes Education Program. This series is intended to highlight best practices and strategies from programs and clinics that have successfully improved the quality of care for people with diabetes or related conditions. Each article in the series is reviewed and follows a standard format developed by the editors of Clinical Diabetes. The following article describes an initiative to improve retinopathy screening rates at the pediatric diabetes clinic of a large academic teaching hospital in Canada.
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Biological sex influences brain anatomy across many species. Sex differences in brain anatomy have classically been attributed to differences in sex chromosome complement (XX versus XY) and/or in levels of gonadal sex steroids released from ovaries and testes. Using the four core genotype (4CG) mouse model in which gonadal sex and sex chromosome complement are decoupled, we previously found that sex hormones and chromosomes influence the volume of distinct brain regions. However, recent studies suggest there may be more complex interactions between hormones and chromosomes, and that circulating steroids can compensate for and/or mask underlying chromosomal effects. Moreover, the impact of pre vs post-pubertal sex hormone exposure on this sex hormone/sex chromosome interplay is not well understood. Thus, we used whole brain high-resolution ex-vivo MRI of intact and pre-pubertally gonadectomized 4CG mice to investigate two questions: 1) Do circulating steroids mask sex differences in brain anatomy driven by sex chromosome complement? And 2) What is the contribution of pre- versus post-pubertal hormones to sex-hormone-dependent differences in brain anatomy? We found evidence of both cooperative and compensatory interactions between sex chromosomes and sex hormones in several brain regions, but the interaction effects were of low magnitude. Additionally, most brain regions affected by sex hormones were sensitive to both pre- and post-pubertal hormones. This data provides further insight into the biological origins of sex differences in brain anatomy.
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Encéfalo/anatomia & histologia , Hormônios Esteroides Gonadais , Caracteres Sexuais , Cromossomo X , Cromossomo Y , Animais , Feminino , Genótipo , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos MutantesRESUMO
OBJECTIVE: The reason for center differences in metabolic control of childhood diabetes is still unknown. We sought to determine to what extent the targets, expectations, and goals that diabetes care professionals have for their patients is a determinant of center differences in metabolic outcomes. RESEARCH DESIGN AND METHODS: Children, under the age of 11 with type 1 diabetes and their parents treated at the study centers participated. Clinical, medical, and demographic data were obtained, along with blood sample for centralized assay. Parents and all members of the diabetes care team completed questionnaires on treatment targets for hemoglobin A1c (HbA1c) and recommended frequency of blood glucose monitoring. RESULTS: Totally 1113 (53% male) children (mean age 8.0 ± 2.1 years) from 18 centers in 17 countries, along with parents and 113 health-care professionals, participated. There were substantial differences in mean HbA1c between centers ranging from 7.3 ± 0.8% (53 mmol/mol ± 8.7) to 8.9 ± 1.1% (74 mmol/mol ± 12.0). Centers with lower mean HbA1c had (1) parents who reported lower targets for their children, (2) health-care professionals that reported lower targets and more frequent testing, and (3) teams with less disagreement about recommended targets. Multiple regression analysis indicated that teams reporting higher HbA1c targets and more target disagreement had parents reporting higher treatment targets. This seemed to partially account for center differences in Hb1Ac. CONCLUSIONS: The diabetes care teams' cohesiveness and perspectives on treatment targets, expectations, and recommendations have an influence on parental targets, contributing to the differences in pediatric diabetes center outcomes.
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Instituições de Assistência Ambulatorial/normas , Atitude do Pessoal de Saúde , Diabetes Mellitus Tipo 1/terapia , Hemoglobinas Glicadas/metabolismo , Criança , Diabetes Mellitus Tipo 1/sangue , Feminino , Humanos , Masculino , Pais/psicologia , Pediatria/normasRESUMO
BACKGROUND: Mild or borderline congenital hypothyroidism [often referred to as mild neonatal hyperthyrotropinemia (MNH)] is characterized by an abnormal newborn screen (NBS), followed by mildly elevated TSH and normal FT4 on confirmatory testing. This condition is increasingly observed, but data regarding optimal management are limited. OBJECTIVE: Examine the use of routine technetium thyroid scanning (TS) in the management of MNH. METHODS: Retrospective study of infants with MNH between 2000 and 2011. We assessed the clinical course of infants with MNH according to TS results; as a comparator, infants with classic congenital hypothyroidism (CH) were analysed in parallel. RESULTS: We identified 69 infants (52% boys) with MNH and 164 (34% boys) with classic CH. TS results were divided into four subgroups: no uptake in 7% of MNH vs 24% of classic CH (P < 0·01), decreased uptake/anatomical abnormalities in 39% vs 46% (p = NS), increased uptake in 35% vs 26% (p = NS) and normal uptake in 19% vs 4% (P < 0·01). In MNH, neither NBS-TSH, confirmatory TSH and FT4, mean LT-4 treatment doses and number of dose escalations, nor post-treatment FT4 and TSH differed among the four subgroups. In contrast, clinical features in infants with classic CH differed among the subgroups. Among MNH infants who reached 3 years of age, trial-off treatment was successful in 6 of 11 (55%) with no apparent difference in success rates among TS subgroups. CONCLUSIONS: The information provided by TS during evaluation of MNH does not predict clinical course; obtaining these scans in infants with MNH may not be an effective use of healthcare resources.
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Hipotireoidismo Congênito/diagnóstico , Triagem Neonatal/métodos , Tecnécio , Hipotireoidismo Congênito/tratamento farmacológico , Feminino , Humanos , Recém-Nascido , Masculino , Estudos Retrospectivos , Tireotropina/metabolismo , Tiroxina/uso terapêuticoRESUMO
All reproductively competent adults have gone through puberty. While key genes and signaling pathways that lead to the onset of sexual maturation are known, the molecular mechanisms that determine when an individual enters puberty are only beginning to be understood. Both genetic and environmental factors determine the timing of puberty. New advances in understanding how environmentally sensitive, yet highly heritable developmental processes are regulated have come from the field of epigenetics. Of note, studies investigating the epigenetic control of the onset of puberty suggest that epigenetic repression of key inhibitory loci may play a fundamental role in the initiation of puberty. Current technologies that not only read out the DNA sequence, but also determine how the DNA is modified in response to the environment, promise new insight into how puberty is regulated, including the identification and understanding of gene regulatory networks that control the biological pathways affecting pubertal timing. Here we review the findings to date and discuss how epigenetic investigation can further our understanding of this fundamental aspect of human development.
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Epigênese Genética/fisiologia , Epigenômica , Puberdade/fisiologia , Maturidade Sexual/fisiologia , Animais , HumanosRESUMO
Purpose: Transgender and gender diverse (TGD) youth in North American clinical reports are predominantly White with relatively high socioeconomic status suggesting that access to gender-affirming care is inequitable. This study examined whether socioeconomic and social determinant of health discrepancies exist between a clinical population of TGD youth and surrounding communities. Methods: Patient postal codes were used to link the Ontario Marginalization Index (ON-MARG) to a clinic-based TGD youth cohort (n = 298). Using ON-MARG, each patient was assigned a quintile score from 1 (least marginalized) to 5 (most marginalized) on four marginalization measures. Mean quintile scores were compared to background populations. Census-based Toronto neighborhood-level data on ethnic diversity and educational status were also examined. Neighborhoods were categorized as highly represented, less represented, or unrepresented based on representation in the clinic cohort. One-way analysis of covariance was used to determine associations between neighborhood-level variables and the degree of neighborhood representation. Results: ON-MARG data demonstrated that clinic patients hailed from areas with more individuals having paid employment. Patients from Toronto and surrounding areas came, in general, from communities with fewer recent immigrants and visible minorities. Highly represented Toronto neighborhoods had smaller proportions of visible minorities and immigrants compared with less and unrepresented neighborhoods. Educational status, represented by adults with bachelor's degrees, was lower among unrepresented neighborhoods. Conclusion: TGD youth seen in clinic, particularly those from Toronto, are disproportionally White and socioeconomically advantaged. Further research is needed to better understand the underrepresentation of racialized and low-socioeconomic status youth and to inform strategies to improve access to care.
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Gender dysphoria (GD) and obesity share commonalities, including associations with mental health comorbidities, disordered eating, body dissatisfaction and may intensify with physical and developmental changes during adolescence. While associations of obesity and gender diversity have been identified, rates of gender diversity among adolescents with obesity remain unclear. The aim was to examine gender diversity among adolescents with obesity in a weight management programme. A single-centre cross-sectional questionnaire study was conducted. Eligible adolescents received the Gender Identity/GD Questionnaire for Adolescents and Adults (GIDYQ-AA), a validated instrument measuring gender diversity and GD. Gender identities, sexual orientations, questionnaire scores, and frequency of GD (GIDYQ-AA score <3) were determined. The relationship of GIDYQ-AA scores and BMI Z-score (BMIz) was assessed. Of 72 consenting youth, 29 assigned females (AF) and 17 assigned males (AM) completed GIDYQ-AA and demographic questions. Seventeen (59%) AF reported non-heterosexual orientations, and 6 (21%) reported non-cisgender identities. One (6%) AM reported non-cisgender identity. Two (4%) AF individuals had GD based on GIDYQ-AA scores. GIDYQ-AA scores did not correlate with BMIz. In conclusion, adolescents with obesity, particularly AF with non-heterosexual orientation, reported high rates of non-cisgender identity and GD. Routine screening for gender-related concerns in weight management settings may be warranted.
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Obesidade Infantil , Programas de Redução de Peso , Humanos , Adolescente , Masculino , Feminino , Estudos Transversais , Obesidade Infantil/epidemiologia , Obesidade Infantil/psicologia , Inquéritos e Questionários , Disforia de Gênero/psicologia , Disforia de Gênero/epidemiologia , Índice de Massa Corporal , Identidade de GêneroRESUMO
CONTEXT: Constitutional delay of puberty (CDP) is highly heritable, but the genetic basis for CDP is largely unknown. Idiopathic hypogonadotropic hypogonadism (IHH) can be caused by rare genetic variants, but in about half of cases, no rare-variant cause is found. OBJECTIVE: To determine whether common genetic variants that influence pubertal timing contribute to CDP and IHH. DESIGN: Case-control study. PARTICIPANTS: 80 individuals with CDP; 301 with normosmic IHH, and 348 with Kallmann syndrome; control genotyping data from unrelated studies. MAIN OUTCOME MEASURES: Polygenic scores (PGS) based on genome-wide association studies for timing of male pubertal hallmarks and age at menarche (AAM). RESULTS: The CDP cohort had higher PGS for male pubertal hallmarks and for AAM compared to controls (for male hallmarks, Cohen's d = 0.85, p = 1 × 10-16; for AAM, d = 0.67, p = 1 × 10-10). The normosmic IHH cohort also had higher PGS for male hallmarks compared to controls, but the difference was smaller (male hallmarks d = 0.20, p = 0.003; AAM d = 0.10, p = 0.055). No differences were seen for the KS cohort compared to controls (male hallmarks d = 0.04, p = 0.45; AAM d = -0.03, p = 0.86). CONCLUSIONS: Common genetic variants that influence pubertal timing in the general population contribute strongly to the genetics of CDP, weakly to normosmic IHH, and potentially not at all to KS. These findings demonstrate that the common-variant genetics of CDP and normosmic IHH are largely but not entirely distinct.
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The capacity of sex to modify behavior in health and illness may stem from biological differences between males and females. One such difference--fundamental to the biological definition of sex--is inequality of X chromosome dosage. Studies of Turner Syndrome (TS) suggest that X-monosomy profoundly alters mammalian brain development. However, use of TS as a model for X chromosome haploinsufficiency is complicated by karyotypic mosaicism, background genetic heterogeneity and ovarian dysgenesis. Therefore, to better isolate X chromosome effects on brain development and identify how these overlap with normative sex differences, we used whole-brain structural imaging to study X-monosomic mice (free of mosaicism and ovarian dysgenesis) alongside their karyotypical normal male and female littermates. We demonstrate that murine X-monosomy (XO) causes (i) accentuation of XX vs XY differences in a set of sexually dimorphic structures including classical foci of sex-hormone action, such as the bed nucleus of the stria terminal and medial amygdala, (ii) parietal and striatal abnormalities that recapitulate those reported TS, and (iii) abnormal development of brain systems relevant for domains of altered cognition and emotion in both murine and human X-monosomy. Our findings suggest an unexpected role for X-linked genes in shaping sexually dimorphic brain development, and an evolutionarily conserved influence of X-linked genes on both cortical and subcortical development in mammals. Furthermore, our murine findings highlight the bed nucleus of the stria terminalis and periaqueductal gray matter as novel neuroanatomical candidates for closer study in TS. Integration of these data with existing genomic knowledge generates a set of novel, testable hypotheses regarding candidate mechanisms for each observed pattern of anatomical variation across XO, XX and XY groups.
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Encéfalo/anatomia & histologia , Caracteres Sexuais , Síndrome de Turner/patologia , Animais , Modelos Animais de Doenças , Feminino , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos MutantesRESUMO
Recent human and rodent brain imaging studies have shown that the shape of the brain can be changed by experience. These mesoscopic alterations in neuroanatomy are hypothesized to be driven by changes at the level of neuronal processes. To examine whether the shape of the brain changes rapidly, we used MRI to examine changes in the volume of the hippocampus across the 4-6 day estrous cycle in the female mouse. It is well known that changing steroid levels across the cycle influence dendritic spine maturation and alter synapse density in the hippocampus; our results show that the estrous cycle is associated with approximately 2-3% changes in hippocampal volume as seen by high-resolution ex-vivo MRI. Changes in hippocampal volume are, moreover, associated with a switch between hippocampal and striatal based navigation strategies in solving the dual choice T-maze in the same mice. A second experiment, using in-vivo MRI, suggests that these changes in hippocampal volume can occur over a 24 hour period. In summary, we show that the brain is highly plastic at a mesoscopic level of resolution detectable by MRI, that volumetric increases and decreases in hippocampal volume follow previously established patterns of changes in neuropil, and that these changes in volume predict changes in cognition.
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Ciclo Estral/fisiologia , Hipocampo/anatomia & histologia , Hipocampo/fisiologia , Aprendizagem em Labirinto/fisiologia , Plasticidade Neuronal/fisiologia , Animais , Cognição , Feminino , Imageamento por Ressonância Magnética , Camundongos , Camundongos Endogâmicos C57BL , Fatores de TempoRESUMO
OBJECTIVE: To examine a large population of infants with mild neonatal hyperthyrotrophinaemia (MNH) and determine prevalence, clinical characteristics and treatment history. METHODS: Retrospective study of infants with MNH followed at The Hospital for Sick Children between 2000 and 2011. MNH was defined by an abnormal newborn screen followed by thyroid-stimulating hormone (TSH) between 5 and 30 mU/l and normal free T4 (FT4) on confirmatory tests. RESULTS: Mild neonatal hyperthyrotrophinaemia represented 22·3% of patients (103/462; 60 boys, 43 girls) within our clinic. Incidence increased from two of 20 in 2000 to 31 of 74 cases in 2010. Seventy eight percent of patients started L-thyroxine (initial dose: 8·3 ± 2·5 mcg/kg). The treated group had higher confirmatory TSH levels (P = 0·001) and had undergone thyroid scintigraphy more often (P = 0·0001) compared with the nontreated group. Evidence of overtreatment was detected in 45% of thyroid function tests obtained during treatment. Among the treated infants who had reached 3 years of age, 45% (N = 14) underwent a trial-off medication. Compared with those not trialled-off therapy, these infants were less likely to have had dose escalations during treatment (P = 0·001). The trial-off treatment was successful in 50% of cases. In the subset of infants with confirmatory TSH >10 mU/l, trial-off therapy was successful in 40%. None of the assessed variables predicted success of trial-off therapy. CONCLUSIONS: Mild neonatal hyperthyrotrophinaemia is an increasingly common diagnosis. It is more common in males and is often transient, but predictors of success of trial-off therapy were not identified. Further studies are needed to determine optimum L-thyroxine dosing and to determine whether treatment improves neurocognitive outcomes.
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Hipotireoidismo Congênito/sangue , Tireotropina/sangue , Hipotireoidismo Congênito/tratamento farmacológico , Hipotireoidismo Congênito/epidemiologia , Feminino , Humanos , Recém-Nascido , Masculino , Triagem Neonatal , Ontário/epidemiologia , Prevalência , Estudos Retrospectivos , Tiroxina/sangue , Tiroxina/uso terapêuticoRESUMO
As we move forward from the current generation of genome-wide association (GWA) studies, additional cohorts of different ancestries will be studied to increase power, fine map association signals, and generalize association results to additional populations. Knowledge of genetic ancestry as well as population substructure will become increasingly important for GWA studies in populations of unknown ancestry. Here we propose genotyping pooled DNA samples using genome-wide SNP arrays as a viable option to efficiently and inexpensively estimate admixture proportion and identify ancestry informative markers (AIMs) in populations of unknown origin. We constructed DNA pools from African American, Native Hawaiian, Latina, and Jamaican samples and genotyped them using the Affymetrix 6.0 array. Aided by individual genotype data from the African American cohort, we established quality control filters to remove poorly performing SNPs and estimated allele frequencies for the remaining SNPs in each panel. We then applied a regression-based method to estimate the proportion of admixture in each cohort using the allele frequencies estimated from pooling and populations from the International HapMap Consortium as reference panels, and identified AIMs unique to each population. In this study, we demonstrated that genotyping pooled DNA samples yields estimates of admixture proportion that are both consistent with our knowledge of population history and similar to those obtained by genotyping known AIMs. Furthermore, through validation by individual genotyping, we demonstrated that pooling is quite effective for identifying SNPs with large allele frequency differences (i.e., AIMs) and that these AIMs are able to differentiate two closely related populations (HapMap JPT and CHB).
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Pool Gênico , Genética Populacional/métodos , Genoma Humano/genética , Filogenia , Povo Asiático/genética , Frequência do Gene/genética , Marcadores Genéticos , Genótipo , Humanos , Análise de Componente Principal , Controle de Qualidade , Reprodutibilidade dos TestesRESUMO
CONTEXT: The melanocortin 3 receptor (MC3R) has recently emerged as a critical regulator of pubertal timing, linear growth, and the acquisition of lean mass in humans and mice. In population-based studies, heterozygous carriers of deleterious variants in MC3R report a later onset of puberty than noncarriers. However, the frequency of such variants in patients who present with clinical disorders of pubertal development is currently unknown. OBJECTIVE: This work aimed to determine whether deleterious MC3R variants are more frequently found in patients clinically presenting with constitutional delay of growth and puberty (CDGP) or normosmic idiopathic hypogonadotropic hypogonadism (nIHH). METHODS: We examined the sequence of MC3R in 362 adolescents with a clinical diagnosis of CDGP and 657 patients with nIHH, experimentally characterized the signaling properties of all nonsynonymous variants found and compared their frequency to that in 5774 controls from a population-based cohort. Additionally, we established the relative frequency of predicted deleterious variants in individuals with self-reported delayed vs normally timed menarche/voice-breaking in the UK Biobank cohort. RESULTS: MC3R loss-of-function variants were infrequent but overrepresented in patients with CDGP (8/362 [2.2%]; OR = 4.17; P = .001). There was no strong evidence of overrepresentation in patients with nIHH (4/657 [0.6%]; OR = 1.15; P = .779). In 246 328 women from the UK Biobank, predicted deleterious variants were more frequently found in those self-reporting delayed (aged ≥16 years) vs normal age at menarche (OR = 1.66; P = 3.90E-07). CONCLUSION: We have found evidence that functionally damaging variants in MC3R are overrepresented in individuals with CDGP but are not a common cause of this phenotype.
Assuntos
Hipogonadismo , Puberdade Tardia , Adolescente , Humanos , Feminino , Animais , Camundongos , Receptor Tipo 3 de Melanocortina , Prevalência , Hipogonadismo/epidemiologia , Hipogonadismo/genética , Hipogonadismo/complicações , Puberdade Tardia/epidemiologia , Puberdade Tardia/genética , Puberdade Tardia/diagnóstico , Puberdade/genética , Transtornos do Crescimento/genéticaRESUMO
BACKGROUND: The use of mHealth apps has shown improved health outcomes in adult populations with type 2 diabetes mellitus. However, this has not been shown in the adolescent type 1 population, despite their predisposition to the use of technology. We hypothesized that a more tailored approach and a strong adherence mechanism is needed for this group. OBJECTIVE: To design, develop, and pilot an mHealth intervention for the management of type 1 diabetes in adolescents. METHODS: We interviewed adolescents with type 1 diabetes and their family caregivers. Design principles were derived from a thematic analysis of the interviews. User-centered design was then used to develop the mobile app bant. In the 12-week evaluation phase, a pilot group of 20 adolescents aged 12-16 years, with a glycated hemoglobin (HbA(1c)) of between 8% and 10% was sampled. Each participant was supplied with the bant app running on an iPhone or iPod Touch and a LifeScan glucometer with a Bluetooth adapter for automated transfers to the app. The outcome measure was the average daily frequency of blood glucose measurement during the pilot compared with the preceding 12 weeks. RESULTS: Thematic analysis findings were the role of data collecting rather than decision making; the need for fast, discrete transactions; overcoming decision inertia; and the need for ad hoc information sharing. Design aspects of the resultant app emerged through the user-centered design process, including simple, automated transfer of glucometer readings; the use of a social community; and the concept of gamification, whereby routine behaviors and actions are rewarded in the form of iTunes music and apps. Blood glucose trend analysis was provided with immediate prompting of the participant to suggest both the cause and remedy of the adverse trend. The pilot evaluation showed that the daily average frequency of blood glucose measurement increased 50% (from 2.4 to 3.6 per day, P = .006, n = 12). A total of 161 rewards (average of 8 rewards each) were distributed to participants. Satisfaction was high, with 88% (14/16 participants) stating that they would continue to use the system. Demonstrating improvements in HbA(1c) will require a properly powered study of sufficient duration. CONCLUSIONS: This mHealth diabetes app with the use of gamification incentives showed an improvement in the frequency of blood glucose monitoring in adolescents with type 1 diabetes. Extending this to improved health outcomes will require the incentives to be tied not only to frequency of blood glucose monitoring but also to patient actions and decision making based on those readings such that glycemic control can be improved.