106 results on '"Barrett TG"'
Search Results
2. Targets and teamwork: Understanding differences in pediatric diabetes centers treatment outcomes
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Skinner, TC, Lange, KS, Hoey, H, Mortensen, HB, Aanstoot, H-J, Castano, L, Skovlund, S, Swift, PGF, Cameron, FJ, Dorchy, HR, Palmert, MR, Kaprio, E, Robert, J-J, Danne, T, Neu, A, Shalitin, S, Chiarelli, F, Chiari, G, Urakami, T, Njolstad, PR, Jarosz-Chobot, PK, Roche, EF, Castro-Correia, CG, Kocova, M, Aman, J, Schonle, E, Barrett, TG, Fisher, L, de Beaufort, CE, Skinner, TC, Lange, KS, Hoey, H, Mortensen, HB, Aanstoot, H-J, Castano, L, Skovlund, S, Swift, PGF, Cameron, FJ, Dorchy, HR, Palmert, MR, Kaprio, E, Robert, J-J, Danne, T, Neu, A, Shalitin, S, Chiarelli, F, Chiari, G, Urakami, T, Njolstad, PR, Jarosz-Chobot, PK, Roche, EF, Castro-Correia, CG, Kocova, M, Aman, J, Schonle, E, Barrett, TG, Fisher, L, and de Beaufort, CE
- Abstract
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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- 2018
3. G153 Type 2 diabetes in children and young people in UK and republic of ireland
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Candler, TP, primary, Mahmoud, O, additional, Barrett, TG, additional, and Hamilton-Shield, JP, additional
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- 2017
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4. Monogenic diabetes syndromes: Locus-specific databases for Alstrom, Wolfram, and Thiamine-responsive megaloblastic anemia
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Astuti, D, Sabir, A, Fulton, P, Zatyka, M, Williams, D, Hardy, C, Milan, G, Favaretto, F, Yu-Wai-Man, P, Rohayem, J, Lopez de Heredia, M, Hershey, T, Tranebjaerg, L, Chen, J-H, Chaussenot, A, Nunes, V, Marshall, B, McAfferty, S, Tillmann, V, Maffei, P, Paquis-Flucklinger, V, Geberhiwot, T, Mlynarski, W, Parkinson, K, Picard, V, Esteban Bueno, G, Dias, R, Arnold, A, Richens, C, Paisey, R, Urano, F, Semple, R, Sinnott, R, Barrett, TG, Astuti, D, Sabir, A, Fulton, P, Zatyka, M, Williams, D, Hardy, C, Milan, G, Favaretto, F, Yu-Wai-Man, P, Rohayem, J, Lopez de Heredia, M, Hershey, T, Tranebjaerg, L, Chen, J-H, Chaussenot, A, Nunes, V, Marshall, B, McAfferty, S, Tillmann, V, Maffei, P, Paquis-Flucklinger, V, Geberhiwot, T, Mlynarski, W, Parkinson, K, Picard, V, Esteban Bueno, G, Dias, R, Arnold, A, Richens, C, Paisey, R, Urano, F, Semple, R, Sinnott, R, and Barrett, TG
- Abstract
We developed a variant database for diabetes syndrome genes, using the Leiden Open Variation Database platform, containing observed phenotypes matched to the genetic variations. We populated it with 628 published disease-associated variants (December 2016) for: WFS1 (n = 309), CISD2 (n = 3), ALMS1 (n = 268), and SLC19A2 (n = 48) for Wolfram type 1, Wolfram type 2, Alström, and Thiamine-responsive megaloblastic anemia syndromes, respectively; and included 23 previously unpublished novel germline variants in WFS1 and 17 variants in ALMS1. We then investigated genotype-phenotype relations for the WFS1 gene. The presence of biallelic loss-of-function variants predicted Wolfram syndrome defined by insulin-dependent diabetes and optic atrophy, with a sensitivity of 79% (95% CI 75%-83%) and specificity of 92% (83%-97%). The presence of minor loss-of-function variants in WFS1 predicted isolated diabetes, isolated deafness, or isolated congenital cataracts without development of the full syndrome (sensitivity 100% [93%-100%]; specificity 78% [73%-82%]). The ability to provide a prognostic prediction based on genotype will lead to improvements in patient care and counseling. The development of the database as a repository for monogenic diabetes gene variants will allow prognostic predictions for other diabetes syndromes as next-generation sequencing expands the repertoire of genotypes and phenotypes. The database is publicly available online at https://lovd.euro-wabb.org.
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- 2017
5. A Cost of Illness Study Evaluating The Burden of Wolfram Syndrome In The United Kingdom
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Eljamel, S, primary, De Stone, S, additional, Ghosh, W, additional, Griffiths, A, additional, Barrett, TG, additional, and Thompson, RS, additional
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- 2016
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6. EURO-WABB: an EU rare diseases registry for Wolfram syndrome, Alstrom syndrome and Bardet-Biedl syndrome
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Farmer, A, Ayme, S, de Heredia, ML, Maffei, P, McCafferty, S, Mlynarski, W, Nunes, V, Parkinson, K, Paquis-Flucklinger, V, Rohayem, J, Sinnott, R, Tillmann, V, Tranebaerg, L, Barrett, TG, Farmer, A, Ayme, S, de Heredia, ML, Maffei, P, McCafferty, S, Mlynarski, W, Nunes, V, Parkinson, K, Paquis-Flucklinger, V, Rohayem, J, Sinnott, R, Tillmann, V, Tranebaerg, L, and Barrett, TG
- Abstract
BACKGROUND: Wolfram, Alström and Bardet-Biedl (WABB) syndromes are rare diseases with overlapping features of multiple sensory and metabolic impairments, including diabetes mellitus, which have caused diagnostic confusion. There are as yet no specific treatments available, little or no access to well characterized cohorts of patients, and limited information on the natural history of the diseases. We aim to establish a Europe-wide registry for these diseases to inform patient care and research. METHODS: EURO-WABB is an international multicenter large-scale observational study capturing longitudinal clinical and outcome data for patients with WABB diagnoses. Three hundred participants will be recruited over 3 years from different sites throughout Europe. Comprehensive clinical, genetic and patient experience data will be collated into an anonymized disease registry. Data collection will be web-based, and forms part of the project's Virtual Research and Information Environment (VRIE). Participants who haven't undergone genetic diagnostic testing for their condition will be able to do so via the project. CONCLUSIONS: The registry data will be used to increase the understanding of the natural history of WABB diseases, to serve as an evidence base for clinical management, and to aid the identification of opportunities for intervention to stop or delay the progress of the disease. The detailed clinical characterisation will allow inclusion of patients into studies of novel treatment interventions, including targeted interventions in small scale open label studies; and enrolment into multi-national clinical trials. The registry will also support wider access to genetic testing, and encourage international collaborations for patient benefit.
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- 2013
7. PSY52 - A Cost of Illness Study Evaluating The Burden of Wolfram Syndrome In The United Kingdom
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Eljamel, S, De Stone, S, Ghosh, W, Griffiths, A, Barrett, TG, and Thompson, RS
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- 2016
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8. Cellular modelling of Alström syndrome in human primary dermal fibroblasts and derived cells
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Semple, RK, primary, Chen, J-H, additional, Paisey, RB, additional, Barrett, TG, additional, and Hales, M, additional
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- 2012
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9. Wolcott-Rallison syndrome: a clinical and genetic study of three children, novel mutation in EIF2AK3 and a review of the literature
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Iyer, S, primary, Korada, M, additional, Rainbow, L, additional, Kirk, J, additional, Brown, RM, additional, Shaw, N, additional, and Barrett, TG, additional
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- 2007
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10. Neurodegeneration and Diabetes: Nationwide Study of Wolfram (DIDMOAD) Syndrome
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Barrett, TG, primary, Bundey, SE, additional, and Collier, DA, additional
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- 1996
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11. Wolcott-Rallison Syndrome: clinical, genetic, and functional study of EIF2AK3 mutations and suggestion of genetic heterogeneity.
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Senée V, Vattem KM, Delépine M, Rainbow LA, Haton C, Lecoq A, Shaw NJ, Robert J, Rooman R, Diatloff-Zito C, Michaud ML, Bin-Abbas B, Taha D, Zabel B, Franceschini P, Topaloglu AK, Lathrop GM, Barrett TG, Nicolino M, and Wek RC
- Abstract
Wolcott-Rallison syndrome (WRS) is a rare autosomal-recessive disorder characterized by the association of permanent neonatal or early-infancy insulin-dependent diabetes, multiple epiphyseal dysplasia and growth retardation, and other variable multisystemic clinical manifestations. Based on genetic studies of two inbred families, we previously identified the gene responsible for this disorder as EIF2AK3, the pancreatic eukaryotic initiation factor 2alpha (eIF2alpha) kinase. Here, we have studied 12 families with WRS, totalling 18 cases. With the exception of one case, all patients carried EIF2AK3 mutations resulting in truncated or missense versions of the protein. Exclusion of EIF2AK3 mutations in the one patient case was confirmed by both linkage and sequence data. The activities of missense versions of EIF2AK3 were characterized in vivo and in vitro and found to have a complete lack of activity in four mutant proteins and residual kinase activity in one. Remarkably, the onset of diabetes was relatively late (30 months) in the patient expressing the partially defective EIF2AK3 mutant and in the patient with no EIF2AK3 involvement (18 months) compared with other patients (<6 months). The patient with no EIF2AK3 involvement did not have any of the other variable clinical manifestations associated with WRS, which supports the idea that the genetic heterogeneity between this variant form of WRS and EIF2AK3 WRS correlates with some clinical heterogeneity. [ABSTRACT FROM AUTHOR]
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- 2004
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12. I10 Adherence to treatment and reduction in bmi sds associated with lower hba1c, 1 year after diagnosis of type 2 diabetes in youth
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Candler, TP, Mahmoud, O, Lynn, RM, Majbar, AA, Barrett, TG, and Hamilton-Shield, JP
- Abstract
ObjectiveTo report outcomes from a national cohort of children and young people with type 2 diabetes (T2DM), 1 year post diagnosisResearch design and methods1 year follow up of a cohort of children (<17 years) with T2DM reported through the British Paediatric Surveillance Unit between April 2015 to April 2016. This established an overall UK incidence of 0.72 per 1 00 000 per year (2.92/100,000 in Asians, 1.67/100,000 Black/African/Caribbean/Black British)ResultsNinety-nine (93%) of the 106 notified cases had data available for one-year review. Of these, seven had been lost to follow up and one had the diagnosis revised. The mean age at follow up was 15.3 years. Of those with data, average BMI SDS was 2.72 with a mean increase of 0.14 SDS over a year (92% remained overweight or obese). Only ~15% of cases achieved a reduction in body weight of 5% or more from baseline. Median HbA1c was 53 mmol/mol (range 31–130 mmol/mol) and ~40% attained the UK national target of <48 mmol/mol. HbA1c was associated with BMI SDS change at 1 year (p=0.007) and clinician reported compliance and attendance concerns (p≤0.0001). In over half of cases, clinicians reported issues with compliance and attendance. Mean clinic attendance was 77%. Metformin was the most frequently used agent in management at baseline (77%) and follow up (87%). Microalbuminuria at 1 year was seen in 16.4% of cases compared to 4.2% at baseline.ConclusionsGood compliance and BMI reduction is associated with better outcomes, one year after diagnosis in early onset T2DM. It is concerning that the prevalence of microalbuminuria increases four-fold in this short time frame.
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- 2018
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13. G153 Type 2 diabetes in children and young people in UK and republic of ireland
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Candler, TP, Mahmoud, O, Barrett, TG, and Hamilton-Shield, JP
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AimsTo estimate the incidence of type 2 diabetes in children under 17 years of age in the UK and Republic of Ireland and characterise the clinical features and co-morbidities present at diagnosis. In 2005, the incidence in the UK of type 2 diabetes in children under 17 years of age was 0.53/100,000/year.MethodsUsing the British Paediatric Surveillance Unit reporting framework, cases of type 2 diabetes diagnosed in children under 17 years of age in the UK and Republic of Ireland between 1stApril 2015 and 30th April 2016 were reported each month.ResultsOne hundred and five cases of type 2 diabetes were identified, giving a UK incidence of 0.72/100,000/year(95% CI 0.58–0.88). Children from ethnic minorities had a significantly higher incidence of type 2 diabetes compared with white children (0.43/ 100,000/year) with incidences of 2.92/100,000/year (~sevenfold) and 1.67/100,000/year (~four-fold), in Asian and Black children respectively. Sixty-six percent of cases were female and 81% had a family history of type 2 diabetes. Thirty-four percent were asymptomatic at diagnosis. Fifty-three percent had osmotic symptoms of diabetes (polyuria, polydipsia, weight loss), 18% had recurrent infections with vulvo-vaginitis frequently reported. Thirty-seven percent had fatty liver disease and 21% were hypertensive at diagnosis.ConclusionsType 2 diabetes is relatively rare in the UK but the incidence is rising when compared with the last 2004/5 BPSU survey. Children from ethnic minorities are significantly over represented compared with white children. Female sex, obesity and family history are strongly associated with the type 2 diabetes in this age group.
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- 2017
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14. Association between mutations in a thyroid hormone transporter and severe X-linked psychomotor retardation.
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Friesema ECH, Grueters A, Biebermann H, Krude H, von Moers A, Reeser M, Barrett TG, Mancilla EE, Svensson J, Kester MHA, Kuiper GGJ, Balkassmi S, Uitterlinden AG, Koehrle J, Rodien P, Halestrap AP, and Visser TJ
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- 2004
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15. Cellular modelling of Alström syndrome in human primary dermal fibroblasts and derived cells
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Timothy Barrett, Richard B Paisey, Robert K. Semple, M Hales, J-H Chen, Semple, RK [0000-0001-6539-3069], Barrett, TG [0000-0002-6873-0750], and Apollo - University of Cambridge Repository
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Retinal degeneration ,Cell type ,Cellular pathology ,lcsh:Cytology ,Cilium ,Adipose tissue ,Cell Biology ,Biology ,medicine.disease ,Bioinformatics ,Ciliopathies ,Cell biology ,Poster Presentation ,medicine ,lcsh:QH573-671 ,Induced pluripotent stem cell ,Alström syndrome - Abstract
Alstrom syndrome (AS) is a complex disorder whose manifestations include retinal degeneration, sensorineural hearing loss, cardiomyopathy, liver fibrosis, and severe insulin resistance. It is caused by biallelic loss-of-function mutations in the ALMS1 gene, encoding a large centrosomal protein of poorly understood function. Although the syndrome encompasses several cardinal features of ciliopathies, primary cilia have been reported to be morphologically normal in primary cells from patients with AS. In order to dissect out the cellular pathology of AS in humans we have now, in a project led by Alstrom UK, assembled a bank of dermal fibroblasts from patients with AS. All 11 cell lines studied to date show normal primary cilia on serum starvation. 3/11 lines express near normal levels of ALMS1 protein at the centrosome despite biallelic ALMS1 mutations, which will permit refinement of existing genotype-phenotype correlations in AS. We have also generated induced pluripotent stem cells that will be differentiated into cell types relevant to the organ-specific pathologies of AS including cardiomyocytes, hepatocytes and adipocytes. Finally we have used lentivirally-mediated expression of the adipose differentiation regulator PPARgamma2 to reprogramme human dermal fibroblasts to adipocytes. We have developed a highly efficient protocol to produce cells that accumulate triglyceride, show a pattern of gene expression consistent with adipocytes, secrete adiponectin and leptin, and respond physiologically to insulin. Collectively these developments constitute a valuable cellular resource for studying the cellular pathology of AS, and may form the basis of preclinical treatment screens in future.
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- 2012
16. Prader-Willi syndrome: guidance for children and transition into adulthood.
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Shaikh MG, Barrett TG, Bridges N, Chung R, Gevers EF, Goldstone AP, Holland A, Kanumakala S, Krone R, Kyriakou A, Livesey EA, Lucas-Herald AK, Meade C, Passmore S, Roche E, Smith C, and Soni S
- Abstract
Prader-Willi syndrome (PWS) is a rare orphan disease and complex genetic neurodevelopmental disorder, with a birth incidence of approximately 1 in 10,000-30,000. Management of people with PWS requires a multi-disciplinary approach, ideally through a multi-disciplinary team (MDT) clinic with community support. Hypotonia, poor feeding and faltering growth are characteristic features in the neonatal period, followed by hyperphagia and risk of rapid weight gain later in childhood. Children and adolescents (CA) with PWS usually display developmental delay and mild learning disability and can develop endocrinopathies, scoliosis, respiratory difficulties (both central and obstructive sleep apnoea), challenging behaviours, skin picking, and mental health issues, especially into adulthood. This consensus statement is intended to be a reference document for clinicians managing children and adolescents (up to 18 years of age) with PWS. It considers the bio-psycho-social domains of diagnosis, clinical assessment, and management in the paediatric setting as well as during and after transition to adult services. The guidance has been developed from information gathered from peer-reviewed scientific reports and from the expertise of a range of experienced clinicians in the United Kingdom and Ireland involved in the care of patients with PWS.
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- 2024
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17. A practical evidence-based approach to management of type 2 diabetes in children and young people (CYP): UK consensus.
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White B, Ng SM, Agwu JC, Barrett TG, Birchmore N, Kershaw M, Drew J, Kavvoura F, Law J, Moudiotis C, Procter E, Paul P, Regan F, Reilly P, Sachdev P, Sakremath R, Semple C, Sharples K, Skae M, Timmis A, Williams E, Wright N, and Soni A
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- Adult, Humans, Child, Adolescent, Comorbidity, Obesity, United Kingdom epidemiology, Diabetes Mellitus, Type 2 diagnosis, Diabetes Mellitus, Type 2 epidemiology, Diabetes Mellitus, Type 2 therapy, Metformin
- Abstract
Background: Type 2 diabetes in young people is an aggressive disease with a greater risk of complications leading to increased morbidity and mortality during the most productive years of life. Prevalence in the UK and globally is rising yet experience in managing this condition is limited. There are no consensus guidelines in the UK for the assessment and management of paediatric type 2 diabetes., Methods: Multidisciplinary professionals from The Association of Children's Diabetes Clinicians (ACDC) and the National Type 2 Diabetes Working Group reviewed the evidence base and made recommendations using the Grading Of Recommendations, Assessment, Development and Evaluation (GRADE) methodology., Results and Discussion: Young people with type 2 diabetes should be managed within a paediatric diabetes team with close working with adult diabetes specialists, primary care and other paediatric specialties. Diagnosis of diabetes type can be challenging with many overlapping features. Diabetes antibodies may be needed to aid diagnosis. Co-morbidities and complications are frequently present at diagnosis and should be managed holistically. Lifestyle change and metformin are the mainstay of early treatment, with some needing additional basal insulin. GLP1 agonists should be used as second-line agents once early ketosis and symptoms are controlled. Glycaemic control improves microvascular but not cardiovascular risk. Reduction in excess adiposity, smoking prevention, increased physical activity and reduction of hypertension and dyslipidaemia are essential to reduce major adverse cardiovascular events., Conclusions: This evidence-based guideline aims to provide a practical approach in managing this condition in the UK., (© 2024. The Author(s).)
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- 2024
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18. Views of children with diabetes from underserved communities, and their families on diabetes, glycaemic control and healthcare provision: A qualitative evidence synthesis.
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Moore TH, Dawson S, Wheeler J, Hamilton-Shield J, Barrett TG, Redwood S, Litchfield I, Greenfield SM, and Searle A
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- Child, Humans, Adolescent, Glycemic Control, Minority Groups, Delivery of Health Care, Qualitative Research, Ethnicity, Diabetes Mellitus
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Aims: Children and young people with diabetes (CYPD) from socio-economically deprived and/or ethnic minority groups tend to have poorer glucose control and greater risk of diabetes-related complications. In this systematic review of qualitative evidence (qualitative evidence synthesis, QES), we aimed to explore the experiences and views of clinical encounters in diabetes care from the perspectives of CYPD and their family/carers from underserved communities and healthcare professionals in diabetes care., Methods: We searched 6 databases to March 2022 with extensive search terms, and used a thematic synthesis following methods of Thomas and Harden., Results: We identified 7 studies and described 11 descriptive themes based on primary and secondary constructs. From these, three "analytical themes" were developed. (1) "Alienation of CYPD" relates to their social identity and interaction with peers, family and health service practitioners in the context of diabetes self- and family/carer management and is impacted by communication in the clinical encounter. (2) "Empowerment of CYPD and family/carers" explores families' understanding of risks and consequences of diabetes and taking responsibility for self- and family/carer management in the context of their socio-cultural background. (3) "Integration of diabetes (into self and family)" focuses on the ability to integrate diabetes self-management into the daily lives of CYPD and family/carers beyond the clinical consultation., Conclusions: The analytical themes are interdependent and provide a conceptual framework from which to explore and strengthen the therapeutic alliance in clinical encounters and to foster greater concordance with treatment plans. Communicating the biomedical aspects of managing diabetes in the clinical encounter is important, but should be balanced with addressing socio-emotional factors important to CYPD and family/carers., (© 2023 The Authors. Diabetic Medicine published by John Wiley & Sons Ltd on behalf of Diabetes UK.)
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- 2023
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19. An effective and cost-saving structured education program teaching dynamic glucose management strategies to a socio-economically deprived cohort with type 1 diabetes in a VIRTUAL setting.
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Pemberton JS, Barrett TG, Dias RP, Kershaw M, Krone R, and Uday S
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- Adolescent, Blood Glucose, Blood Glucose Self-Monitoring, Child, Glucose, Glycated Hemoglobin analysis, Humans, Hypoglycemic Agents therapeutic use, Insulin, Diabetes Mellitus, Type 1 drug therapy, Hypoglycemia prevention & control
- Abstract
Objectives: Compare the clinical and cost-effectiveness of an established face to face (F2F) structured education program to a new remote (VIRTUAL) program teaching dynamic glucose management (DynamicGM) to children and young people with type 1 diabetes (CYPD) using continuous glucose monitoring (CGM). To ascertain the most effective DynamicGM strategies predicting time in range (TIR) (3.9-10.0 mmol/L) and incorporating these into a user-friendly teaching aid., Design and Methods: Effectiveness of the F2F and VIRTUAL programs were ascertained by comparing the mean change (Δ) from baseline to 6 months in HbA1c, TIR and severe hypoglycemia. Delivery cost for the two programs were evaluated. Factors predicting TIR in the combined cohort were determined and incorporated into a user-friendly infographic., Results: First 50 graduates per group were evaluated. The mean difference in Δ HbA1c, Δ TIR and Δ episodes of severe hypoglycemia between VIRTUAL and F2F groups were 1.16 (p = 0.47), 0.76 (p = 0.78) and -0.06 (p = 0.61) respectively. Delivery cost per 50 CYPD for VIRTUAL and F2F were $5752 and $7020, respectively. The strongest predictors of TIR (n = 100) were short bursts of exercise (10-40 min) to lower hyperglycemia (p < 0.001), using trend arrow adjustment tools (p < 0.001) and adjusting pre-meal bolus timing based on trend arrows (p < 0.01). These strategies were translated into a GAME (Stop highs), SET (Stay in target), MATCH (Prevent lows) mnemonic., Conclusion: Teaching DynamicGM VIRTUALLY is just as effective as F2F delivery and cost saving. Short bursts of exercise and using CGM trend arrows to adjust insulin dose and timing improves TIR., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
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- 2022
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20. Clinical characteristics and treatment requirements of children with autosomal recessive pseudohypoaldosteronism.
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Bandhakavi M, Wanaguru A, Ayuk L, Kirk JM, Barrett TG, Kershaw M, Högler W, and Shaw NJ
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- Adolescent, Adult, Child, Child, Preschool, Consanguinity, Epithelial Sodium Channels genetics, Family, Female, Genes, Recessive, Homozygote, Humans, Male, Mutation, Pseudohypoaldosteronism genetics, Pseudohypoaldosteronism mortality, Retrospective Studies, United Kingdom epidemiology, Young Adult, Pseudohypoaldosteronism diagnosis, Pseudohypoaldosteronism therapy
- Abstract
Introduction: Autosomal recessive forms of pseudohypoaldosteronism are caused by genetic defects in the epithelial sodium channel. Little is known about the long-term outcome and medication needs during childhood and adolescence., Objective: This study reports a single-centre experience of children affected with this ultra-rare condition over a 37-year period., Methods: We report the clinical presentation, growth, neuro-development, associated conditions, mortality and medication dosing and administration for 12 affected children from eight families., Results: All children were presented within the first 2 weeks of life with life-threatening, severe hyperkalaemia and hyponatraemia. All parents were consanguineous and of South Asian, Middle Eastern or African ethnic origin. Eight children had homozygous mutations in the SCNN1A and SCNN1G genes, encoding the epithelial sodium channel subunits alpha and gamma, respectively, including one novel mutation. Three children died (25%) and two (16%) had severe neurological impairment post-cardiac arrest secondary to hyperkalaemia. One affected female had a successful pregnancy at the age of 28 years., Conclusion: Despite high mortality and morbidity in this condition, survival with normal physical and neurological outcome is possible, justifying intensive management to prevent electrolyte imbalance.
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- 2021
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21. DYNAMIC: Dynamic glucose management strategies delivered through a structured education program improves time in range in a socioeconomically deprived cohort of children and young people with type 1 diabetes with a history of hypoglycemia.
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Pemberton JS, Kershaw M, Dias R, Idkowiak J, Mohamed Z, Saraff V, Barrett TG, Krone R, and Uday S
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- Adolescent, Age Factors, Blood Glucose metabolism, Child, Cohort Studies, Diabetes Mellitus, Type 1 complications, Female, Glycated Hemoglobin metabolism, Humans, Hypoglycemia diagnosis, Hypoglycemia etiology, Male, Time Factors, Blood Glucose Self-Monitoring instrumentation, Diabetes Mellitus, Type 1 blood, Diabetes Mellitus, Type 1 drug therapy, Hypoglycemia prevention & control, Hypoglycemic Agents therapeutic use, Patient Education as Topic
- Abstract
Objectives: Create and evaluate the effectiveness of a structured education program in children and young people (CYP) with type 1 diabetes using continuous glucose monitoring (CGM)., Design and Methods: Step 1: CGM devices were evaluated for predetermined criteria using a composite score. Step 2: The education program was developed following review of international structured education guidance, dynamic glucose management (DynamicGM) literature, award-winning diabetes educators' websites, and CGM user feedback. Step 3: Program effectiveness was assessed at six months by change in time below range (TBR) (<3.9mmol/L), time in range (TIR) (3.9-10.0mmol/L), time above range level 2 (TAR2) (>13.9mmol/L), severe hypoglycemia and HbA1c using a paired T-test. A DynamicGM score was developed to assess proactive glucose management. Factors predicting TBR and TIR were assessed using regression analysis., Results: Dexcom G6 was chosen for integrated CGM (iCGM) status and highest composite score (29/30). Progressive DynamicGM strategies were taught through five sessions delivered over two months. Fifty CYP (23 male) with a mean (±SD) age and diabetes duration of 10.2 (±4.8) and 5.2 (±3.7) years respectively, who completed the education program were prospectively evaluated. Evaluation at six months showed a significant reduction in TBR (10.4% to 2.1%, p<.001), TAR2 (14.1% to 7.3%, p<.001), HbA1c [7.4 to 7.1% (57.7 to 53.8 mmol/mol), p<.001] and severe hypoglycemic episodes (10 to 1, p<.05); TIR increased (47.4% to 57.0%, p<.001). Number of Dexcom followers (p<.05) predicted reduction in TBR and DynamicGM score (p<.001) predicted increased TIR., Conclusion: Teaching DynamicGM strategies successfully improves TIR and reduces hypoglycemia., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
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- 2021
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22. Causes, patterns and severity of androgen excess in 487 consecutively recruited pre- and post-pubertal children.
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Idkowiak J, Elhassan YS, Mannion P, Smith K, Webster R, Saraff V, Barrett TG, Shaw NJ, Krone N, Dias RP, Kershaw M, Kirk JM, Högler W, Krone RE, O'Reilly MW, and Arlt W
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- Adolescent, Androstenedione blood, Child, Child, Preschool, Dehydroepiandrosterone blood, Dehydroepiandrosterone Sulfate blood, Endocrine System Diseases blood, Endocrine System Diseases pathology, Female, Humans, Male, Puberty, Precocious blood, Puberty, Precocious epidemiology, Retrospective Studies, Risk Factors, Severity of Illness Index, Sexual Maturation physiology, Testosterone blood, Androgens blood, Endocrine System Diseases epidemiology, Endocrine System Diseases etiology, Puberty blood
- Abstract
Objective Androgen excess in childhood is a common presentation and may signify sinister underlying pathology. Data describing its patterns and severity are scarce, limiting the information available for clinical decision processes. Here, we examined the differential diagnostic value of serum DHEAS, androstenedione (A4) and testosterone in childhood androgen excess. Design Retrospective review of all children undergoing serum androgen measurement at a single center over 5 years. Methods Serum A4 and testosterone were measured by tandem mass spectrometry and DHEAS by immunoassay. Patients with at least one increased androgen underwent phenotyping by clinical notes review. Results In 487 children with simultaneous DHEAS, A4 and testosterone measurements, we identified 199 with androgen excess (140 pre- and 59 post-pubertal). Premature adrenarche (PA) was the most common pre-pubertal diagnosis (61%), characterized by DHEAS excess in 85%, while A4 and testosterone were only increased in 26 and 9% respectively. PCOS was diagnosed in 40% of post-pubertal subjects, presenting equally frequent with isolated excess of DHEAS (29%) or testosterone (25%) or increases in both A4 and testosterone (25%). CAH patients (6%) predominantly had A4 excess (86%); testosterone and DHEAS were increased in 50 and 33% respectively. Concentrations increased above the two-fold upper limit of normal were mostly observed in PA for serum DHEAS (>20-fold in the single case of adrenocortical carcinoma) and in CAH for serum androstenedione. Conclusions Patterns and severity of childhood androgen excess provide pointers to the underlying diagnosis and can be used to guide further investigations.
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- 2019
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23. Treatment adherence and BMI reduction are key predictors of HbA1c 1 year after diagnosis of childhood type 2 diabetes in the United Kingdom.
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Candler TP, Mahmoud O, Lynn RM, Majbar AA, Barrett TG, and Shield JPH
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- Adolescent, Age of Onset, Blood Glucose analysis, Blood Glucose metabolism, Child, Female, Follow-Up Studies, Glycated Hemoglobin analysis, Humans, Male, Population Surveillance, Prognosis, Time Factors, United Kingdom epidemiology, Young Adult, Body Mass Index, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 diagnosis, Diabetes Mellitus, Type 2 epidemiology, Glycated Hemoglobin metabolism, Treatment Adherence and Compliance statistics & numerical data, Weight Loss physiology
- Abstract
Background/objective: Type 2 Diabetes (T2DM) is increasing in childhood especially among females and South-Asians. Our objective was to report outcomes from a national cohort of children and adolescents with T2DM 1 year following diagnosis., Methods: Clinician reported, 1-year follow-up of a cohort of children (<17 years) diagnosed with T2DM reported through the British Paediatric Surveillance Unit (BPSU) (April 2015-April 2016)., Results: One hundred (94%) of 106 baseline cases were available for review. Of these, five were lost to follow up and one had a revised diagnosis. Mean age at follow up was 15.3 years. Median BMI standard deviation scores (SDS) was 2.81 with a decrease of 0.13 SDS over a year. HbA1c <48 mmol/mol (UK target) was achieved in 38.8%. logHbA1c was predicted by clinician reported compliance and attendance concerns (β = 0.12, P = <0.0001) and change in body mass index (BMI) SDS at 1-year (β = 0.13, P=0.007). In over 50%, clinicians reported issues with compliance and attendance. Mean clinic attendance was 75%. Metformin was the most frequently used treatment at baseline (77%) and follow-up (87%). Microalbuminuria prevalence at 1-year was 16.4% compared to 4.2% at baseline and was associated with a higher HbA1c compared to those without microalbuminuria (60 vs 49 mmol/mol, P = 0.03)., Conclusions: Adherence to treatment and a reduction in BMI appear key to better outcomes a year after T2DM diagnosis. Retention and clinic attendance are concerning. The prevalence of microalbuminuria has increased 4-fold in the year following diagnosis and was associated with higher HbA1c., (© 2018 The Authors. Pediatric Diabetes published by John Wiley & Sons Ltd.)
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- 2018
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24. Continuing rise of Type 2 diabetes incidence in children and young people in the UK.
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Candler TP, Mahmoud O, Lynn RM, Majbar AA, Barrett TG, and Shield JPH
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- Adolescent, Asia ethnology, Body Mass Index, Child, Diabetes Mellitus, Type 2 complications, Diabetes Mellitus, Type 2 ethnology, Female, Humans, Incidence, Ireland epidemiology, Male, Pediatric Obesity epidemiology, Pediatric Obesity ethnology, Prospective Studies, Sex Distribution, Surveys and Questionnaires, United Kingdom epidemiology, West Indies ethnology, White People ethnology, Diabetes Mellitus, Type 2 epidemiology
- Abstract
Aims: To estimate the incidence of Type 2 diabetes in children aged <17 years, compare this with similar data 10 years ago, and characterize clinical features at diagnosis in the UK and Republic of Ireland., Methods: Using the British Paediatric Surveillance Unit reporting framework, cases of Type 2 diabetes diagnosed in children aged <17 years between 1 April 2015 and 30 April 2016 were reported each month., Results: A total of 106 cases were reported, giving a UK incidence of 0.72/100 000 (95% CI 0.58-0.88). Children from ethnic minorities had significantly higher incidence compared with white children (0.44/100 000) with rates of 2.92/100 000 and 1.67/100 000, in Asian and BACBB (black/African/Caribbean/black British) children respectively. Sixty-seven percent were girls and 81% had a family history of Type 2 diabetes. The mean BMI sd score at diagnosis was 2.89 (2.88, girls; 2.92, boys); 81% were obese. Children of Asian ethnicity had a significantly lower BMI sd score compared with white children (P<0.001). There was a trend in increased incidence from 2005 to 2015, with a rate ratio of 1.35 (95% CI 0.99-1.84), although this was not statistically significant (P=0.062). There was statistical evidence of increased incidence among girls (P=0.03) and children of South-Asian ethnicity (P=0.01) when comparing the 2005 and 2015 surveys., Conclusions: Type 2 diabetes remains far less common than Type 1 diabetes in childhood in the UK, but the number of cases continues to rise, with significantly increased incidence among girls and South-Asian children over a decade. Female gender, family history, non-white ethnicity and obesity were found to be strongly associated with the condition., (© 2018 The Authors. Diabetic Medicine published by John Wiley & Sons Ltd on behalf of Diabetes UK.)
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- 2018
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25. Targets and teamwork: Understanding differences in pediatric diabetes centers treatment outcomes.
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Skinner TC, Lange KS, Hoey H, Mortensen HB, Aanstoot HJ, Castaňo L, Skovlund S, Swift PG, Cameron FJ, Dorchy HR, Palmert MR, Kaprio E, Robert JJ, Danne T, Neu A, Shalitin S, Chiarelli F, Chiari G, Urakami T, Njølstad PR, Jarosz-Chobot PK, Roche EF, Castro-Correia CG, Kocova M, Åman J, Schönle E, Barrett TG, Fisher L, and de Beaufort CE
- Subjects
- Child, Diabetes Mellitus, Type 1 blood, Female, Humans, Male, Parents psychology, Pediatrics standards, Ambulatory Care Facilities standards, Attitude of Health Personnel, Diabetes Mellitus, Type 1 therapy, Glycated Hemoglobin metabolism
- Abstract
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., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
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- 2018
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26. Quantitative Brain MRI in Congenital Adrenal Hyperplasia: In Vivo Assessment of the Cognitive and Structural Impact of Steroid Hormones.
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Webb EA, Elliott L, Carlin D, Wilson M, Hall K, Netherton J, Reed J, Barrett TG, Salwani V, Clayden JD, Arlt W, Krone N, Peet AC, and Wood AG
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- Adolescent, Adrenal Hyperplasia, Congenital drug therapy, Adrenal Hyperplasia, Congenital metabolism, Adrenal Hyperplasia, Congenital psychology, Adult, Brain drug effects, Brain metabolism, Choline metabolism, Cross-Sectional Studies, Dose-Response Relationship, Drug, Female, Glucocorticoids administration & dosage, Glucocorticoids therapeutic use, Humans, Magnetic Resonance Imaging methods, Magnetic Resonance Spectroscopy methods, Middle Aged, Neuropsychological Tests, Psychometrics, Quality of Life, Young Adult, Adrenal Hyperplasia, Congenital diagnostic imaging, Brain diagnostic imaging, Cognition drug effects, Glucocorticoids pharmacology
- Abstract
Context: Brain white matter hyperintensities are seen on routine clinical imaging in 46% of adults with congenital adrenal hyperplasia (CAH). The extent and functional relevance of these abnormalities have not been studied with quantitative magnetic resonance imaging (MRI) analysis., Objective: To examine white matter microstructure, neural volumes, and central nervous system (CNS) metabolites in CAH due to 21-hydroxylase deficiency (21OHD) and to determine whether identified abnormalities are associated with cognition, glucocorticoid, and androgen exposure., Design, Setting, and Participants: A cross-sectional study at a tertiary hospital including 19 women (18 to 50 years) with 21OHD and 19 age-matched healthy women., Main Outcome Measure: Recruits underwent cognitive assessment and brain imaging, including diffusion weighted imaging of white matter, T1-weighted volumetry, and magnetic resonance spectroscopy for neural metabolites. We evaluated white matter microstructure by using tract-based spatial statistics. We compared cognitive scores, neural volumes, and metabolites between groups and relationships between glucocorticoid exposure, MRI, and neurologic outcomes., Results: Patients with 21OHD had widespread reductions in white matter structural integrity, reduced volumes of right hippocampus, bilateral thalami, cerebellum, and brainstem, and reduced mesial temporal lobe total choline content. Working memory, processing speed, and digit span and matrix reasoning scores were reduced in patients with 21OHD, despite similar education and intelligence to controls. Patients with 21OHD exposed to higher glucocorticoid doses had greater abnormalities in white matter microstructure and cognitive performance., Conclusion: We demonstrate that 21OHD and current glucocorticoid replacement regimens have a profound impact on brain morphology and function. If reversible, these CNS markers are a potential target for treatment.
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- 2018
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27. Evaluation of human dermal fibroblasts directly reprogrammed to adipocyte-like cells as a metabolic disease model.
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Chen JH, Goh KJ, Rocha N, Groeneveld MP, Minic M, Barrett TG, Savage D, and Semple RK
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- Humans, Mutation genetics, PPAR gamma genetics, PPAR gamma metabolism, Stem Cells pathology, Adipocytes pathology, Cellular Reprogramming, Dermis pathology, Fibroblasts pathology, Metabolic Diseases pathology, Models, Biological
- Abstract
Adipose tissue is the primary tissue affected in most single gene forms of severe insulin resistance, and growing evidence has implicated it as a site at which many risk alleles for insulin resistance identified in population-wide studies might exert their effect. There is thus increasing need for human adipocyte models in which to interrogate the function of known and emerging genetic risk variants. However, primary adipocyte cultures, existing immortalised cell lines and stem-cell based models all have significant biological or practical limitations. In an attempt to widen the repertoire of human cell models in which to study adipocyte-autonomous effects of relevant human genetic variants, we have undertaken direct reprogramming of skin fibroblasts to adipocyte-like cells by employing an inducible recombinant lentivirus overexpressing the master adipogenic transcription factor PPARγ2. Doxycycline-driven expression of PPARγ2 and adipogenic culture conditions converted dermal fibroblasts into triglyceride-laden cells within days. The resulting cells recapitulated most of the crucial aspects of adipocyte biology in vivo , including the expression of mature adipocyte markers, secreted high levels of the adipokine adiponectin, and underwent lipolysis when treated with isoproterenol/3-isobutyl-1-methylxanthine (IBMX). They did not, however, exhibit insulin-inducible glucose uptake, and withdrawal of doxycycline produced rapid delipidation and loss of adipogenic markers. This protocol was applied successfully to a panel of skin cells from individuals with monogenic severe insulin resistance; however, surprisingly, even cell lines harbouring mutations causing severe, generalised lipodystrophy accumulated large lipid droplets and induced adipocyte-specific genes. The direct reprogramming protocol of human dermal fibroblasts to adipocyte-like cells we established is simple, fast and efficient, and has the potential to generate cells which can serve as a tool to address some, though not all, aspects of adipocyte function in the presence of endogenous disease-causing mutations., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2017. Published by The Company of Biologists Ltd.)
- Published
- 2017
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28. Empowering youth sport environments: Implications for daily moderate-to-vigorous physical activity and adiposity.
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Fenton SAM, Duda JL, Appleton PR, and Barrett TG
- Abstract
Background: Evidence suggests involvement in youth sport does not guarantee daily guidelines for moderate-to-vigorous physical activity (MVPA) are met, and participation may not mitigate the risks associated with physical inactivity. The need to promote higher habitual MVPA engagement amongst children active in the youth sport context has therefore been underlined. Framed by self-determination theory, the aim of the present study was to examine the implications of the motivational climate created in youth sport, for children's daily engagement in MVPA and associated adiposity. Specifically, we sought to test a motivational sequence in which children's perceptions of an empowering coach-created motivational climate were related to autonomous and controlled motivation, which in turn predicted sport-related enjoyment. Finally, enjoyment was assumed to predict accelerometer assessed daily MVPA and, following this, adiposity., Methods: Male and female youth sport participants aged 9-16 years ( n = 112) completed multi-section questionnaires assessing their perceptions of the motivational climate created in youth sport (i.e., autonomy supportive, task involving, socially supportive), autonomous and controlled motivation, and sport-related enjoyment. Daily MVPA engagement was determined via 7 days of accelerometry. Percent body fat (BF%) was estimated using bio-electrical impedance analysis., Results: Path analysis revealed perceptions of an empowering motivational climate positively predicted players' autonomous motivation, and in turn, sport-related enjoyment. Enjoyment was also significantly negatively related to players' BF%, via a positive association with daily MVPA., Conclusion: Fostering more empowering youth sport environments may hold implications for the prevention of excess adiposity, through encouraging higher habitual MVPA engagement. Findings may inform the optimal design of youth sport settings for MVPA promotion, and contribute towards associated healthy weight maintenance amongst youth active in this context. Longitudinal and intervention studies are required to confirm these results.
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- 2017
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29. Microstructural abnormalities in white and gray matter in obese adolescents with and without type 2 diabetes.
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Nouwen A, Chambers A, Chechlacz M, Higgs S, Blissett J, Barrett TG, and Allen HA
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- Adolescent, Anisotropy, Brain Mapping, Diabetes Mellitus, Type 2 complications, Diffusion Magnetic Resonance Imaging, Female, Humans, Image Processing, Computer-Assisted, Male, Nerve Fibers, Myelinated pathology, Neural Pathways diagnostic imaging, Obesity complications, Diabetes Mellitus, Type 2 pathology, Gray Matter diagnostic imaging, Magnetic Resonance Imaging, Obesity pathology, White Matter diagnostic imaging
- Abstract
Aims/hypotheses: In adults, type 2 diabetes and obesity have been associated with structural brain changes, even in the absence of dementia. Some evidence suggested similar changes in adolescents with type 2 diabetes but comparisons with a non-obese control group have been lacking. The aim of the current study was to examine differences in microstructure of gray and white matter between adolescents with type 2 diabetes, obese adolescents and healthy weight adolescents., Methods: Magnetic resonance imaging data were collected from 15 adolescents with type 2 diabetes, 21 obese adolescents and 22 healthy weight controls. Volumetric differences in the gray matter between the three groups were examined using voxel based morphology, while tract based spatial statistics was used to examine differences in the microstructure of the white matter., Results: Adolescents with type 2 diabetes and obese adolescents had reduced gray matter volume in the right hippocampus, left putamen and caudate, bilateral amygdala and left thalamus compared to healthy weight controls. Type 2 diabetes was also associated with significant regional changes in fractional anisotropy within the corpus callosum, fornix, left inferior fronto-occipital fasciculus, left uncinate, left internal and external capsule. Fractional anisotropy reductions within these tracts were explained by increased radial diffusivity, which may suggest demyelination of white matter tracts. Mean diffusivity and axial diffusivity did not differ between the groups., Conclusion/interpretation: Our data shows that adolescent obesity alone results in reduced gray matter volume and that adolescent type 2 diabetes is associated with both white and gray matter abnormalities.
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- 2017
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30. Monogenic diabetes syndromes: Locus-specific databases for Alström, Wolfram, and Thiamine-responsive megaloblastic anemia.
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Astuti D, Sabir A, Fulton P, Zatyka M, Williams D, Hardy C, Milan G, Favaretto F, Yu-Wai-Man P, Rohayem J, López de Heredia M, Hershey T, Tranebjaerg L, Chen JH, Chaussenot A, Nunes V, Marshall B, McAfferty S, Tillmann V, Maffei P, Paquis-Flucklinger V, Geberhiwot T, Mlynarski W, Parkinson K, Picard V, Bueno GE, Dias R, Arnold A, Richens C, Paisey R, Urano F, Semple R, Sinnott R, and Barrett TG
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Exons, Family Health, Female, Genetic Association Studies, Genetic Variation, Genotype, Homozygote, Humans, Male, Phenotype, Prognosis, Sensitivity and Specificity, Thiamine Deficiency genetics, Young Adult, Anemia, Megaloblastic genetics, Databases, Genetic, Diabetes Mellitus genetics, Hearing Loss, Sensorineural genetics, Thiamine Deficiency congenital, Wolfram Syndrome genetics
- Abstract
We developed a variant database for diabetes syndrome genes, using the Leiden Open Variation Database platform, containing observed phenotypes matched to the genetic variations. We populated it with 628 published disease-associated variants (December 2016) for: WFS1 (n = 309), CISD2 (n = 3), ALMS1 (n = 268), and SLC19A2 (n = 48) for Wolfram type 1, Wolfram type 2, Alström, and Thiamine-responsive megaloblastic anemia syndromes, respectively; and included 23 previously unpublished novel germline variants in WFS1 and 17 variants in ALMS1. We then investigated genotype-phenotype relations for the WFS1 gene. The presence of biallelic loss-of-function variants predicted Wolfram syndrome defined by insulin-dependent diabetes and optic atrophy, with a sensitivity of 79% (95% CI 75%-83%) and specificity of 92% (83%-97%). The presence of minor loss-of-function variants in WFS1 predicted isolated diabetes, isolated deafness, or isolated congenital cataracts without development of the full syndrome (sensitivity 100% [93%-100%]; specificity 78% [73%-82%]). The ability to provide a prognostic prediction based on genotype will lead to improvements in patient care and counseling. The development of the database as a repository for monogenic diabetes gene variants will allow prognostic predictions for other diabetes syndromes as next-generation sequencing expands the repertoire of genotypes and phenotypes. The database is publicly available online at https://lovd.euro-wabb.org., (© 2017 The Authors. **Human Mutation published by Wiley Periodicals, Inc.)
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- 2017
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31. Refining genotype-phenotype correlation in Alström syndrome through study of primary human fibroblasts.
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Chen JH, Geberhiwot T, Barrett TG, Paisey R, and Semple RK
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Background: Alström syndrome (AS), featuring retinal dystrophy, neuronal deafness, cardiomyopathy, metabolic syndrome, and diffuse fibrosis, is caused by biallelic mutations in the centrosomal protein ALMS1. Genotype-phenotype correlation has been suggested without assessment of ALMS1 expression., Methods: ALMS1 expression (real-time PCR and immunocytochemistry) and cilia formation (immunocytochemistry) were assessed in fibroblasts from deeply phenotyped volunteers diagnosed with AS recruited from a dedicated AS Service. Exome sequencing was used in two participants without convincing biallelic ALMS1 mutations, and BBS2 (Bardet-Biedl syndrome 2) protein expression was assessed in one patient with biallelic BBS2 mutations. Hedgehog-induced GLI1 expression and PDGFA signaling was assessed using quantitative real-time PCR, immunoblotting, or immunostaining of fixed cells after stimulation., Results: In 16 of the patient cell lines examined, ALMS1 protein was undetectable (14 with biallelic loss-of-function (LoF) mutations), and in two, ALMS1 staining was equivocal (one with biallelic LoF mutations). In five lines, ALMS1 expression was normal using at least one fixation method (one with biallelic LoF mutations). These differences were not accounted for by major differences in ALMS1 mRNA expression. Exome sequencing of two participants with normal ALMS1 expression identified biallelic LoF BBS2 mutations in one. No second, known ciliopathy mutation was found in the other patient, who had one LoF ALMS1 mutation. Phenotypes were milder or atypical in participants with preserved ALMS1 immunostaining, even when two with likely alternative genetic diagnoses were excluded. All cells studied developed normal cilia, ALMS1 and BBS2 mutant cells showed normal Hedgehog-induced upregulation of GLI1 expression, and PDGFA signaling was normal in ALMS1-deficient cells., Conclusion: Milder or atypical presentations of AS should prompt genetic evaluation for alternative, clinically overlapping ciliopathies. A subgroup of patients with bona fide ALMS1 defects have milder phenotypes due to residual ALMS1 expression, which may be more important than mutation site.
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- 2017
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32. Steroid Sulfatase Deficiency and Androgen Activation Before and After Puberty.
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Idkowiak J, Taylor AE, Subtil S, O'Neil DM, Vijzelaar R, Dias RP, Amin R, Barrett TG, Shackleton CH, Kirk JM, Moss C, and Arlt W
- Subjects
- Adolescent, Adult, Child, Cholestenone 5 alpha-Reductase genetics, Cholestenone 5 alpha-Reductase metabolism, Cross-Sectional Studies, Dehydroepiandrosterone blood, Dehydroepiandrosterone urine, Dehydroepiandrosterone Sulfate blood, Dehydroepiandrosterone Sulfate urine, Humans, Ichthyosis, X-Linked genetics, Male, Metabolome, Metabolomics, Multiplex Polymerase Chain Reaction, Mutation, Testosterone blood, Testosterone urine, Young Adult, Dehydroepiandrosterone metabolism, Dehydroepiandrosterone Sulfate metabolism, Ichthyosis, X-Linked metabolism, Puberty metabolism, Steryl-Sulfatase genetics, Testosterone metabolism
- Abstract
Context: Steroid sulfatase (STS) cleaves the sulfate moiety off steroid sulfates, including dehydroepiandrosterone (DHEA) sulfate (DHEAS), the inactive sulfate ester of the adrenal androgen precursor DHEA. Deficient DHEA sulfation, the opposite enzymatic reaction to that catalyzed by STS, results in androgen excess by increased conversion of DHEA to active androgens. STS deficiency (STSD) due to deletions or inactivating mutations in the X-linked STS gene manifests with ichthyosis, but androgen synthesis and metabolism in STSD have not been studied in detail yet., Patients and Methods: We carried out a cross-sectional study in 30 males with STSD (age 6-27 y; 13 prepubertal, 5 peripubertal, and 12 postpubertal) and 38 age-, sex-, and Tanner stage-matched healthy controls. Serum and 24-hour urine steroid metabolome analysis was performed by mass spectrometry and genetic analysis of the STS gene by multiplex ligation-dependent probe amplification and Sanger sequencing., Results: Genetic analysis showed STS mutations in all patients, comprising 27 complete gene deletions, 1 intragenic deletion and 2 missense mutations. STSD patients had apparently normal pubertal development. Serum and 24-hour urinary DHEAS were increased in STSD, whereas serum DHEA and testosterone were decreased. However, total 24-hour urinary androgen excretion was similar to controls, with evidence of increased 5α-reductase activity in STSD. Prepubertal healthy controls showed a marked increase in the serum DHEA to DHEAS ratio that was absent in postpubertal controls and in STSD patients of any pubertal stage., Conclusions: In STSD patients, an increased 5α-reductase activity appears to compensate for a reduced rate of androgen generation by enhancing peripheral androgen activation in affected patients. In healthy controls, we discovered a prepubertal surge in the serum DHEA to DHEAS ratio that was absent in STSD, indicative of physiologically up-regulated STS activity before puberty. This may represent a fine tuning mechanism for tissue-specific androgen activation preparing for the major changes in androgen production during puberty.
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- 2016
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33. Os odontoideum in wolcott-rallison syndrome: a case series of 4 patients.
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Dias RP, Buchanan CR, Thomas N, Lim S, Solanki G, Connor SE, Barrett TG, and Kapoor RR
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- Adolescent, Adult, Child, Child, Preschool, Diabetes Mellitus, Type 1 diagnostic imaging, Diabetes Mellitus, Type 1 genetics, Epiphyses diagnostic imaging, Exons genetics, Female, Humans, Infant, Male, Mutation, Osteochondrodysplasias diagnostic imaging, Osteochondrodysplasias genetics, Radiography, Young Adult, eIF-2 Kinase genetics, Diabetes Mellitus, Type 1 diagnosis, Epiphyses abnormalities, Osteochondrodysplasias diagnosis
- Abstract
Wolcott-Rallison Syndrome is the commonest cause of neonatal diabetes in consanguineous families. It is associated with liver dysfunction, epiphyseal dysplasia, and developmental delay. It is caused by mutations in eukaryotic translation initiation factor 2-α kinase 3 (EIF2AK3).We report 4 children with WRS and Os Odontoideum resulting in significant neurological compromise. This cervical spine abnormality has not previously been described in this syndrome. This additional evidence broadens the clinical spectrum of this syndrome and confirms the role of EIF2AK3 in skeletal development. Furthermore, Os Odontoideum needs to be actively screened for in WRS patients to prevent neurological and respiratory compromise.
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- 2016
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34. Sarco(endo)plasmic reticulum ATPase is a molecular partner of Wolfram syndrome 1 protein, which negatively regulates its expression.
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Zatyka M, Da Silva Xavier G, Bellomo EA, Leadbeater W, Astuti D, Smith J, Michelangeli F, Rutter GA, and Barrett TG
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- Animals, COS Cells, Cell Line, Tumor, Cells, Cultured, Chlorocebus aethiops, Dithiothreitol pharmacology, Gene Expression Regulation, Humans, Insulin Secretion, Mice, Mice, Knockout, Calcium metabolism, Insulin metabolism, Membrane Proteins metabolism, Sarcoplasmic Reticulum Calcium-Transporting ATPases metabolism
- Abstract
Wolfram syndrome is an autosomal recessive disorder characterized by neurodegeneration and diabetes mellitus. The gene responsible for the syndrome (WFS1) encodes an endoplasmic reticulum (ER)-resident transmembrane protein that is involved in the regulation of the unfolded protein response (UPR), intracellular ion homeostasis, cyclic adenosine monophosphate production and regulation of insulin biosynthesis and secretion. In this study, single cell Ca(2+) imaging with fura-2 and direct measurements of free cytosolic ATP concentration ([ATP]CYT) with adenovirally expressed luciferase confirmed a reduced and delayed rise in cytosolic free Ca(2+) concentration ([Ca(2+)]CYT), and additionally, diminished [ATP]CYT rises in response to elevated glucose concentrations in WFS1-depleted MIN6 cells. We also observed that sarco(endo)plasmic reticulum ATPase (SERCA) expression was elevated in several WFS1-depleted cell models and primary islets. We demonstrated a novel interaction between WFS1 and SERCA by co-immunoprecipitation in Cos7 cells and with endogenous proteins in human neuroblastoma cells. This interaction was reduced when cells were treated with the ER stress inducer dithiothreitol. Treatment of WFS1-depleted neuroblastoma cells with the proteasome inhibitor MG132 resulted in reduced accumulation of SERCA levels compared with wild-type cells. Together these results reveal a role for WFS1 in the negative regulation of SERCA and provide further insights into the function of WFS1 in calcium homeostasis., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)
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- 2015
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35. A truncating TPO mutation (Y55X) in patients with hypothyroidism and total iodide organification defect.
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Cangul H, Darendeliler F, Saglam Y, Kucukemre B, Kendall M, Boelaert K, Barrett TG, and Maher ER
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- Adolescent, Child, Child, Preschool, DNA Mutational Analysis, Female, Humans, Infant, Male, Siblings, Autoantigens genetics, Congenital Hypothyroidism genetics, Iodide Peroxidase genetics, Iron-Binding Proteins genetics, Mutation
- Abstract
Unlabelled: Absract Purpose: Mutations in the TPO gene have been reported to cause congenital hypothyroidism (CH), and our aim in this study was to determine the genetic basis of congenital hypothyroidism in two affected children coming from a consanguineous family., Methods: Since CH is usually inherited in autosomal recessive manner in consanguineous/multi case-families, we adopted a two-stage strategy of genetic linkage studies and targeted sequencing of the candidate genes. First we investigated the potential genetic linkage of the family to any known CH locus using microsatellite markers and then screened for mutations in linked-gene by Sanger sequencing., Results: The family showed potential linkage to the TPO gene and we detected a non-sense mutation (Y55X) in both cases that had total iodode organification defect (TIOD). The mutation segregated with disease status in the family. Y55X is the only truncating mutation in the exon 2 of the TPO gene reported in the literature and results in the earliest stop codon known in the gene to date., Conclusions: This study confirms the pathogenicity of Y55X mutation and demonstrates that a nonsense mutation in the amino-terminal coding region of the TPO gene could totally abolish the function of the TPO enzyme leading to TIOD. Thus it helps to establish a strong genotype/phenotype correlation associated with this mutation. It also highlights the importance of molecular genetic studies in the definitive diagnosis and accurate classification of CH.
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- 2015
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36. A nonsense thyrotropin receptor gene mutation (R609X) is associated with congenital hypothyroidism and heart defects.
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Cangul H, Bas VN, Saglam Y, Kendall M, Barrett TG, Maher ER, and Aycan Z
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- Base Sequence, Congenital Hypothyroidism complications, Congenital Hypothyroidism pathology, DNA Mutational Analysis, Female, Haplotypes genetics, Heart Defects, Congenital complications, Heart Defects, Congenital pathology, Homozygote, Humans, Infant, Newborn, Male, Microsatellite Repeats, Molecular Sequence Data, Pedigree, Prognosis, Codon, Nonsense genetics, Congenital Hypothyroidism genetics, Heart Defects, Congenital genetics, Receptors, Thyrotropin genetics
- Abstract
Congenital hypothyroidism (CH), one of the most important preventable causes of mental retardation, is a clinical condition characterized by thyroid hormone deficiency in newborns. CH is most often caused by defects in thyroid development leading to thyroid dysgenesis. The thyroid-stimulating hormone receptor (TSHR) is the main known gene causing thyroid dysgenesis in consanguineous families with CH. In this study, we aim to determine the genetic alteration in a case with congenital hypothyroidism and heart defects coming from a consanguineous family. We utilized genetic linkage analysis and direct sequencing to achieve our aim. Our results revealed that the family showed linkage to the TSHR locus, and we detected a homozygous nonsense mutation (R609X) in the case. Apart from other cases with the same mutation, our case had accompanying cardiac malformations. Although cardiac malformations are not uncommon in sporadic congenital hypothyroidism, here, they are reported for the first time with R609X mutation in a familial case.
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- 2014
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37. One Base Deletion (c.2422delT) in the TPO Gene Causes Severe Congenital Hypothyroidism.
- Author
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Cangül H, Doğan M, Sağlam Y, Kendall M, Boelaert K, Barrett TG, and Maher ER
- Subjects
- Child, Congenital Hypothyroidism diagnosis, Congenital Hypothyroidism enzymology, DNA Mutational Analysis, Female, Genetic Association Studies, Genetic Linkage, Genetic Predisposition to Disease, Haplotypes, Heredity, Homozygote, Humans, Pedigree, Phenotype, Risk Factors, Severity of Illness Index, Siblings, Autoantigens genetics, Congenital Hypothyroidism genetics, Iodide Peroxidase genetics, Iron-Binding Proteins genetics, Mutation
- Abstract
Objective: Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder and mutations in the TPO gene have been reported to cause CH. Our aim in this study was to determine the genetic basis of CH in two affected individuals coming from a consanguineous family., Methods: Since CH is usually inherited in autosomal recessive manner in consanguineous/multi-case families, we adopted a two-stage strategy of genetic linkage studies and targeted sequencing of the candidate genes. First, we investigated the potential genetic linkage of the family to any known CH locus using microsatellite markers and then screened for mutations in linked-gene by Sanger sequencing., Results: The family showed potential linkage to the TPO gene and we detected a deletion (c.2422delT) in both cases. The mutation segregated with disease status in the family., Conclusion: This study demonstrates that a single base deletion in the carboxyl-terminal coding region of the TPO gene could cause CH and helps to establish a genotype/phenotype correlation associated with the mutation. The study also highlights the importance of molecular genetic studies in the definitive diagnosis and accurate classification of CH.
- Published
- 2014
- Full Text
- View/download PDF
38. An essential splice site mutation (c.317+1G>A) in the TSHR gene leads to severe thyroid dysgenesis.
- Author
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Cangul H, Saglam H, Saglam Y, Eren E, Dogan D, Kendall M, Tarim O, Maher ER, and Barrett TG
- Subjects
- Female, Humans, Infant, Newborn, Male, Mutation, Congenital Hypothyroidism genetics, Receptors, Thyrotropin genetics, Thyroid Dysgenesis genetics
- Abstract
Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder and 2% of cases have familial origin. Our aim in this study was to determine the genetic alterations in two siblings with CH coming from a consanguineous family. Because CH is often inherited in autosomal recessive manner in consanguineous/multicase-families, we first performed genetic linkage studies to all known causative CH loci followed by conventional sequencing of the linked gene. The family showed potential linkage to the TSHR locus, and we detected an essential splice site mutation (c.317+1G>A) in both siblings. RT-PCR analysis confirmed the functionality of the mutation. The mutation was homozygous in the cases whereas heterozygous in carrier parents and an unaffected sibling. Here we conclude that thyroid agenesis in both siblings in this study originates from c.317+1G>A splice site mutation in the TSHR gene, and this study underlines the importance of detailed molecular genetic studies in the definitive diagnosis and classification of CH.
- Published
- 2014
- Full Text
- View/download PDF
39. A deletion including exon 2 of the TSHR gene is associated with thyroid dysgenesis and severe congenital hypothyroidism.
- Author
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Cangul H, Schoenmakers NA, Saglam H, Doganlar D, Saglam Y, Eren E, Kendall M, Tarim O, Barrett TG, Chatterjee K, and Maher ER
- Subjects
- Adolescent, Child, Preschool, Consanguinity, Exons, Female, Humans, Infant, Newborn, Reverse Transcriptase Polymerase Chain Reaction, Sequence Deletion, Young Adult, Congenital Hypothyroidism genetics, Receptors, Thyrotropin genetics, Thyroid Dysgenesis genetics
- Abstract
Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder and 2% of cases have a familial origin. Our aim in this study was to determine the genetic alterations in two siblings with CH coming from a consanguineous family. As CH is often inherited in an autosomal recessive manner in consanguineous/multi case-families, we first performed genetic linkage studies to all known causative CH loci followed by conventional sequencing of the linked gene. The family showed potential linkage to the TSHR locus and our attempts to amplify and sequence exon 2 of the TSHR gene continuously failed. Subsequent RT-PCR analysis using mRNA and corresponding cDNA showed a large deletion including the exon 2 of the gene. The deletion was homozygous in affected cases whilst heterozygous in carrier parents. Here we conclude that CH in both siblings of this study originates from a large deletion including the exon 2 of the TSHR gene. This study demonstrates that full sequence analysis in a candidate CH gene might not always be enough to detect genetic alterations, and additional analyses such as RT-PCR and MLPA might be necessary to describe putative genetic causes of the disease in some cases. It also underlines the importance of detailed molecular genetic studies in the definitive diagnosis and classification of CH.
- Published
- 2014
- Full Text
- View/download PDF
40. A truncating DUOX2 mutation (R434X) causes severe congenital hypothyroidism.
- Author
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Cangul H, Aycan Z, Kendall M, Bas VN, Saglam Y, Barrett TG, and Maher ER
- Subjects
- Congenital Hypothyroidism physiopathology, Consanguinity, Dual Oxidases, Female, Genetic Markers, Humans, Infant, Newborn, Male, Microsatellite Repeats genetics, Pedigree, Severity of Illness Index, Codon, Nonsense, Congenital Hypothyroidism genetics, NADPH Oxidases genetics
- Abstract
Mutations in DUOX2 have been reported to cause congenital hypothyroidism (CH), and our aim in this study was to determine the genetic basis of CH in two affected individuals coming from a consanguineous family. Because CH is usually inherited in autosomal recessive manner in consanguineous/multicase families, we adopted a two-stage strategy of genetic linkage studies and targeted sequencing of the candidate genes. First, we investigated the potential genetic linkage of the family to any known CH locus using microsatellite markers and then screened for mutations in linked genes by Sanger sequencing. The family showed potential linkage to DUOX2 locus and we detected a nonsense mutation (R434X) in both cases and the mutation segregated with disease status in the family. This study highlights the importance of molecular genetic studies in the definitive diagnosis and classification of CH, and it also suggests a new clinical testing strategy using next-generation sequencing in all primary CH cases.
- Published
- 2014
- Full Text
- View/download PDF
41. Novel truncating thyroglobulin gene mutations associated with congenital hypothyroidism.
- Author
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Cangul H, Boelaert K, Dogan M, Saglam Y, Kendall M, Barrett TG, and Maher ER
- Subjects
- Chromosome Mapping, Cohort Studies, DNA genetics, Female, Haplotypes genetics, Homozygote, Humans, Male, Microsatellite Repeats genetics, Sequence Analysis, DNA, Codon, Nonsense genetics, Congenital Hypothyroidism genetics, Consanguinity, Family, Pedigree, Thyroglobulin genetics
- Abstract
Mutations in the thyroglobulin (TG) gene have been reported to cause congenital hypothyroidism (CH) and we have been investigating the genetic architecture of CH in a large cohort of consanguineous/multi-case families. Our aim in this study was to determine the genetic basis of CH in four affected individuals coming from two separate consanguineous families. Since CH is usually inherited in autosomal recessive manner in consanguineous/multi-case families, we adopted a two-stage strategy of genetic linkage studies and targeted sequencing of the TG gene. First we investigated the potential genetic linkage of families to any known CH locus using microsatellite markers and then determined the pathogenic mutations in linked-genes by Sanger sequencing. Both families showed potential linkage to TG locus and we detected two previously unreported nonsense TG mutations (p.Q630X and p.W637X) that segregated with the disease status in both families. This study highlights the importance of molecular genetic studies in the definitive diagnosis and classification of CH, and also adds up to the limited number of nonsense TG mutations in the literature. It also suggests a new clinical testing strategy using next-generation sequencing in all primary CH cases.
- Published
- 2014
- Full Text
- View/download PDF
42. Clinical utility gene card for: Alström Syndrome - update 2013.
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Marshall JD, Maffei P, Beck S, Barrett TG, Paisey R, and Naggert JK
- Subjects
- Alstrom Syndrome therapy, Genetic Testing, Humans, Alstrom Syndrome diagnosis, Alstrom Syndrome genetics, Genes
- Published
- 2013
- Full Text
- View/download PDF
43. Comparison of the clinical scoring systems in Silver-Russell syndrome and development of modified diagnostic criteria to guide molecular genetic testing.
- Author
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Dias RP, Nightingale P, Hardy C, Kirby G, Tee L, Price S, Macdonald F, Barrett TG, and Maher ER
- Subjects
- Adolescent, Child, Child, Preschool, Chromosome Aberrations, Cohort Studies, DNA Methylation, Female, Humans, Infant, Male, Phenotype, RNA, Long Noncoding genetics, ROC Curve, Young Adult, Genetic Testing methods, Silver-Russell Syndrome diagnosis, Silver-Russell Syndrome genetics
- Abstract
Background: About half of all children with a clinical diagnosis of Silver-Russell syndrome (SRS) have a detectable molecular genetic abnormality (maternal uniparental disomy of chromosome upd(7)mat or hypomethylation of H19 differentially methylated region (DMR). The selection of children for molecular genetic testing can be difficult for non-specialists because of the broad phenotypic spectrum of SRS and the tendency of the facial features to mitigate during late childhood. Several clinical scoring systems for SRS have been developed by specialist researchers, but the utility of these for guiding molecular genetic testing in routine clinical practice has not been established., Objectives: To evaluate the utility of four published clinical scoring systems for genetic testing in a cohort of patients referred to a clinical service laboratory., Patients: Individuals with suspected SRS referred for molecular genetic testing of H19 DMR methylation status or upd(7)mat., Results: 36 of 139 (25.9%) patients referred for testing had a genetic abnormality identified. Comparison of four published clinical scoring systems demonstrated that all included subjective criteria that could be difficult for the general clinician to assess. We developed a novel, simplified, scoring system utilising four objective, easily measured parameters that performed similarly to the most sensitive and specific published scoring system., Discussion: Effective utilisation of genetic testing by clinicians without specialist clinical genetics training will be facilitated by the development of targeted testing protocols that are based on robust objective clinical features and are designed for use in a busy clinical practice rather than a research setting.
- Published
- 2013
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44. EURO-WABB: an EU rare diseases registry for Wolfram syndrome, Alström syndrome and Bardet-Biedl syndrome.
- Author
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Farmer A, Aymé S, de Heredia ML, Maffei P, McCafferty S, Młynarski W, Nunes V, Parkinson K, Paquis-Flucklinger V, Rohayem J, Sinnott R, Tillmann V, Tranebjaerg L, and Barrett TG
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Databases as Topic, European Union, Female, Genetic Testing, Humans, Infant, International Cooperation, Male, Research Design, Alstrom Syndrome, Bardet-Biedl Syndrome, Rare Diseases, Registries, Wolfram Syndrome
- Abstract
Background: Wolfram, Alström and Bardet-Biedl (WABB) syndromes are rare diseases with overlapping features of multiple sensory and metabolic impairments, including diabetes mellitus, which have caused diagnostic confusion. There are as yet no specific treatments available, little or no access to well characterized cohorts of patients, and limited information on the natural history of the diseases. We aim to establish a Europe-wide registry for these diseases to inform patient care and research., Methods: EURO-WABB is an international multicenter large-scale observational study capturing longitudinal clinical and outcome data for patients with WABB diagnoses. Three hundred participants will be recruited over 3 years from different sites throughout Europe. Comprehensive clinical, genetic and patient experience data will be collated into an anonymized disease registry. Data collection will be web-based, and forms part of the project's Virtual Research and Information Environment (VRIE). Participants who haven't undergone genetic diagnostic testing for their condition will be able to do so via the project., Conclusions: The registry data will be used to increase the understanding of the natural history of WABB diseases, to serve as an evidence base for clinical management, and to aid the identification of opportunities for intervention to stop or delay the progress of the disease. The detailed clinical characterisation will allow inclusion of patients into studies of novel treatment interventions, including targeted interventions in small scale open label studies; and enrolment into multi-national clinical trials. The registry will also support wider access to genetic testing, and encourage international collaborations for patient benefit.
- Published
- 2013
- Full Text
- View/download PDF
45. Thyroid dyshormonogenesis is mainly caused by TPO mutations in consanguineous community.
- Author
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Cangul H, Aycan Z, Olivera-Nappa A, Saglam H, Schoenmakers NA, Boelaert K, Cetinkaya S, Tarim O, Bober E, Darendeliler F, Bas V, Demir K, Aydin BK, Kendall M, Cole T, Högler W, Chatterjee VK, Barrett TG, and Maher ER
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Female, Humans, Infant, Infant, Newborn, Male, Mutation, Missense, Pakistan, Thyroid Hormones biosynthesis, Thyroid Hormones genetics, Turkey, Congenital Hypothyroidism genetics, Consanguinity, Iodide Peroxidase genetics
- Abstract
Objective: In this study, we aimed to investigate the genetic background of thyroid dyshormonogenesis (TDH)., Context: Thyroid dyshormonogenesis comprises 10-15% of all cases of congenital hypothyroidism (CH), which is the most common neonatal endocrine disorder, and might result from disruptions at any stage of thyroid hormone biosynthesis. Currently seven genes (NIS, TPO, PDS, TG, IYD, DUOX2 and DUOXA2) have been implicated in the aetiology of the disease., Design: As TDH is mostly inherited in an autosomal recessive manner, we planned to conduct the study in consanguineous/multi-case families., Patients: One hundred and four patients with congenital TDH all coming from consanguineous and/or multi-case families., Measurements: Initially, we performed potential linkage analysis of cases to all seven causative-TDH loci as well as direct sequencing of the TPO gene in cases we could not exclude linkage to this locus. In addition, in silico analyses of novel missense mutations were carried out., Results: TPO had the highest potential for linkage and we identified 21 TPO mutations in 28 TDH cases showing potential linkage to this locus. Four of 10 distinct TPO mutations detected in this study were novel (A5T, Y55X, E596X, D633N)., Conclusions: This study underlines the importance of molecular genetic studies in diagnosis, classification and prognosis of CH and proposes a comprehensive mutation screening by new sequencing technology in all newly diagnosed primary CH cases., (© 2012 John Wiley & Sons Ltd.)
- Published
- 2013
- Full Text
- View/download PDF
46. Home urine C-peptide creatinine ratio (UCPCR) testing can identify type 2 and MODY in pediatric diabetes.
- Author
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Besser RE, Shields BM, Hammersley SE, Colclough K, McDonald TJ, Gray Z, Heywood JJ, Barrett TG, and Hattersley AT
- Subjects
- Adolescent, Algorithms, Child, Cohort Studies, Creatinine urine, Diabetes Mellitus, Type 1 diagnosis, Diabetes Mellitus, Type 1 physiopathology, Diabetes Mellitus, Type 1 urine, Diabetes Mellitus, Type 2 diagnosis, Diabetes Mellitus, Type 2 physiopathology, Diagnosis, Differential, Disease Progression, Family, Female, Humans, Male, Outpatient Clinics, Hospital, Postprandial Period, Self Care, Sensitivity and Specificity, United Kingdom, C-Peptide urine, Diabetes Mellitus, Type 2 urine, Down-Regulation
- Abstract
Background: Making the correct diabetes diagnosis in children is crucial for lifelong management. Type 2 diabetes and maturity onset diabetes of the young (MODY) are seen in the pediatric setting, and can be difficult to discriminate from type 1 diabetes. Postprandial urinary C-peptide creatinine ratio (UCPCR) is a non-invasive measure of endogenous insulin secretion that has not been tested as a diagnostic tool in children or in patients with diabetes duration <5 yr. We aimed to assess whether UCPCR can discriminate type 1 diabetes from MODY and type 2 in pediatric diabetes., Methods: Two-hour postprandial UCPCR was measured in 264 patients aged <21 yr (type 1, n = 160; type 2, n = 41; and MODY, n = 63). Receiver operating characteristic curves were used to identify the optimal UCPCR cutoff for discriminating diabetes subtypes., Results: UCPCR was lower in type 1 diabetes [0.05 (<0.03-0.39) nmol/mmol median (interquartile range)] than in type 2 diabetes [4.01 (2.84-5.74) nmol/mmol, p < 0.0001] and MODY [3.51 (2.37-5.32) nmol/mmol, p < 0.0001]. UCPCR was similar in type 2 diabetes and MODY (p = 0.25), so patients were combined for subsequent analyses. After 2-yr duration, UCPCR ≥ 0.7 nmol/mmol has 100% sensitivity [95% confidence interval (CI): 92-100] and 97% specificity (95% CI: 91-99) for identifying non-type 1 (MODY + type 2 diabetes) from type 1 diabetes [area under the curve (AUC) 0.997]. UCPCR was poor at discriminating MODY from type 2 diabetes (AUC 0.57)., Conclusions: UCPCR testing can be used in diabetes duration greater than 2 yr to identify pediatric patients with non-type 1 diabetes. UCPCR testing is a practical non-invasive method for use in the pediatric outpatient setting., (© 2013 John Wiley & Sons A/S.)
- Published
- 2013
- Full Text
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47. Identification of homozygous WFS1 mutations (p.Asp211Asn, p.Gln486*) causing severe Wolfram syndrome and first report of male fertility.
- Author
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Haghighi A, Haghighi A, Setoodeh A, Saleh-Gohari N, Astuti D, and Barrett TG
- Subjects
- Adult, Child, Preschool, Female, Homozygote, Humans, Iran, Male, Pedigree, Wolfram Syndrome etiology, Fertility genetics, Membrane Proteins genetics, Mutation, Wolfram Syndrome genetics
- Abstract
Wolfram syndrome (WFS) is a neurodegenerative genetic condition characterized by juvenile-onset of diabetes mellitus and optic atrophy. We studied clinical features and the molecular basis of severe WFS (neurodegenerative complications) in two consanguineous families from Iran. A clinical and molecular genetic investigation was performed in the affected and healthy members of two families. The clinical diagnosis of WFS was confirmed by the existence of diabetes mellitus and optic atrophy in the affected patients, who in addition had severe neurodegenerative complications. Sequencing of WFS1 was undertaken in one affected member from each family. Targeted mutations were tested in all members of relevant families. Patients had most of the reported features of WFS. Two affected males in the first family had fathered unaffected children. We identified two homozygous mutations previously reported with apparently milder phenotypes: family 1: c.631G>A (p.Asp211Asn) in exon 5, and family 2: c.1456C>T (p.Gln486*) in exon 8. Heterozygous carriers were unaffected. This is the first report of male Wolfram patients who have successfully fathered children. Surprisingly, they also had almost all the complications associated with WFS. Our report has implications for genetic counseling and family planning advice for other affected families.
- Published
- 2013
- Full Text
- View/download PDF
48. Vacuolar-type H+-ATPase V1A subunit is a molecular partner of Wolfram syndrome 1 (WFS1) protein, which regulates its expression and stability.
- Author
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Gharanei S, Zatyka M, Astuti D, Fenton J, Sik A, Nagy Z, and Barrett TG
- Subjects
- Apoptosis genetics, Carrier Proteins, Cell Cycle genetics, Cell Line, Endoplasmic Reticulum Chaperone BiP, Endoplasmic Reticulum Stress, Gene Expression Regulation, Heat-Shock Proteins genetics, Heat-Shock Proteins metabolism, Humans, Membrane Proteins genetics, Neurons metabolism, Protein Binding, Protein Interaction Domains and Motifs, Protein Stability, Protein Transport, Proton Pumps metabolism, Secretory Vesicles metabolism, Sodium-Potassium-Exchanging ATPase chemistry, Sodium-Potassium-Exchanging ATPase metabolism, Vacuolar Proton-Translocating ATPases chemistry, Membrane Proteins metabolism, Protein Subunits metabolism, Vacuolar Proton-Translocating ATPases metabolism
- Abstract
Wolfram syndrome is an autosomal recessive disorder characterized by neurodegeneration and diabetes mellitus. The gene responsible for the syndrome (WFS1) encodes an endoplasmic reticulum (ER)-resident transmembrane protein that also localizes to secretory granules in pancreatic beta cells. Although its precise functions are unknown, WFS1 protein deficiency affects the unfolded protein response, intracellular ion homeostasis, cell cycle progression and granular acidification. In this study, immunofluorescent and electron-microscopy analyses confirmed that WFS1 also localizes to secretory granules in human neuroblastoma cells. We demonstrated a novel interaction between WFS1 and the V1A subunit of the H(+) V-ATPase (proton pump) by co-immunoprecipitation in human embryonic kidney (HEK) 293 cells and with endogenous proteins in human neuroblastoma cells. We mapped the interaction to the WFS1-N terminal, but not the C-terminal domain. V1A subunit expression was reduced in WFS1 stably and transiently depleted human neuroblastoma cells and depleted NT2 (human neuron-committed teratocarcinoma) cells. This reduced expression was not restored by adenoviral overexpression of BiP (immunoglobulin-binding protein) to correct the ER stress. Protein stability assays demonstrated that the V1A subunit was degraded more rapidly in WFS1 depleted neuroblastoma cells compared with wild-type; however, proteosomal inhibition did not restore the expression of the V1A subunit. Cell cycle assays measuring p21(cip) showed reduced levels in WFS1 depleted cells, and an inverse association between p21(cip) expression and apoptosis. We conclude that WFS1 has a specific interaction with the V1A subunit of H(+) ATPase; this interaction may be important both for pump assembly in the ER and for granular acidification.
- Published
- 2013
- Full Text
- View/download PDF
49. Clinical characteristics and management of cranial diabetes insipidus in infants.
- Author
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Karthikeyan A, Abid N, Sundaram PC, Shaw NJ, Barrett TG, Högler W, and Kirk JM
- Subjects
- Humans, Infant, Infant, Newborn, Infant, Premature, Magnetic Resonance Imaging, Retrospective Studies, Diabetes Insipidus therapy, Skull pathology
- Abstract
Aim: Cranial diabetes insipidus (CDI) is rare in infants with no guidelines on its management. We describe the first case series, characterizing the clinical features and treatment challenges., Method: Retrospective case note review of infants diagnosed with CDI between April 1992 and February 2011., Results: Nineteen infants (52% male) were identified. Eight were born preterm. Median (range) age at diagnosis was 24 days (5-300); preterm babies were younger at diagnosis (21 vs. 46 days). In 58% (11/19) of infants, hypernatraemia was discovered incidentally. In 37% of cases there was associated midline anomalies, however, only four patients (21%) had absent posterior pituitary signal on a magnetic resonance imaging brain scan. The most frequent (5/19) underlying diagnosis was septo-optic dysplasia. Eight patients had isolated CDI and 11 had multiple pituitary hormone deficiencies. Isolated CDI tended to be more common in preterm, compared to term babies (p=0.11). Des-amino arginine vasopressin (DDAVP) was administered intranasally in eight and orally in 11 infants. Plasma sodium nadir following DDAVP administration was lower following intranasal compared to an oral route of administration (median: 128 vs. 133 mmol/L, p=0.022). No cases resolved on follow-up., Conclusions: CDI in infants is often diagnosed incidentally. Aetiology, clinical, and imaging features are very variable, with some differences between preterm and term infants. Oral DDAVP appears to be superior to intranasal with less pronounced serum sodium fluctuations.
- Published
- 2013
- Full Text
- View/download PDF
50. TSHR is the main causative locus in autosomal recessively inherited thyroid dysgenesis.
- Author
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Cangul H, Aycan Z, Saglam H, Forman JR, Cetinkaya S, Tarim O, Bober E, Cesur Y, Kurtoglu S, Darendeliler F, Bas V, Eren E, Demir K, Kiraz A, Aydin BK, Karthikeyan A, Kendall M, Boelaert K, Shaw NJ, Kirk J, Högler W, Barrett TG, and Maher ER
- Subjects
- Adolescent, Adult, Child, Child, Preschool, Dimerization, Female, Genes, Recessive genetics, Genetic Association Studies, Humans, Male, Microsatellite Repeats genetics, Point Mutation genetics, Protein Structure, Secondary, Protein Structure, Tertiary, Receptors, Thyrotropin chemistry, Young Adult, Congenital Hypothyroidism genetics, Receptors, Thyrotropin genetics, Thyroid Dysgenesis genetics
- Abstract
Congenital hypothyroidism (CH) is the most common neonatal endocrine disorder and results in mental retardation if untreated. Eighty-five percent of CH cases are due to disruptions in thyroid organogenesis and are mostly sporadic, but about 2% of thyroid dysgenesis is familial, indicating the involvement of genetic factors in the aetiology of the disease. In this study, we aimed to investigate the Mendelian (single-gene) causes of non-syndromic and non-goitrous congenital hypothyroidism (CHNG) in consanguineous or multi-case families. Here we report the results of the second part (n=105) of our large cohort (n=244), representing the largest such cohort in the literature, and interpret the overall results of the whole cohort. Additionally, 50 sporadic cases with thyroid dysgenesis and 400 unaffected control subjects were included in the study. In familial cases, first, we performed potential linkage analysis of four known genes causing CHNG (TSHR, PAX8, TSHB, and NKX2-5) using microsatellite markers and then examined the presence of mutations in these genes by direct sequencing. In addition, in silico analyses of the predicted structural effects of TSHR mutations were performed and related to the mutation specific disease phenotype. We detected eight new TSHR mutations and a PAX8 mutation but no mutations in TSHB and NKX2-5. None of the biallelic TSHR mutations detected in familial cases were present in the cohort of 50 sporadic cases. Genotype/phenotype relationships were established between TSHR mutations and resulting clinical presentations. Here we conclude that TSHR mutations are the main detectable cause of autosomal recessively inherited thyroid dysgenesis. We also outline a new genetic testing strategy for the investigation of suspected autosomal recessive non-goitrous CH.
- Published
- 2012
- Full Text
- View/download PDF
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