Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
J Clin Endocrinol Metab ; 108(7): 1676-1685, 2023 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-36639249

RESUMO

CONTEXT: Prader-Willi syndrome (PWS) is a rare neurobehavioral-metabolic disease caused by the lack of paternally expressed genes in the chromosome 15q11-q13 region, characterized by hypotonia, neurocognitive problems, behavioral difficulties, endocrinopathies, and hyperphagia resulting in severe obesity if not controlled. OBJECTIVE: The primary end point was change from baseline in hyperphagia using the Hyperphagia Questionnaire for Clinical Trials (HQ-CT). Other end points included Global Impression Scores, and changes in body composition, behaviors, and hormones. METHODS: In DESTINY PWS, a 13-week, randomized, double-blind, placebo-controlled, phase 3 trial, 127 participants with PWS aged 4 years and older with hyperphagia were randomly assigned 2:1 to diazoxide choline extended-release tablet (DCCR) or placebo. RESULTS: DCCR did not significantly improve hyperphagia (HQ-CT least-square mean (LSmean) [SE] -5.94 [0.879] vs -4.27 [1.145]; P = .198), but did so in participants with severe hyperphagia (LSmean [SE] -9.67 [1.429] vs -4.26 [1.896]; P = .012). Two of 3 secondary end points were improved (Clinical Global Impression of Improvement [CGI-I]; P = .029; fat mass; P = .023). In an analysis of results generated pre-COVID, the primary (HQ-CT; P = .037) and secondary end points were all improved (CGI-I; P = .015; Caregiver Global Impression of Change; P = .031; fat mass; P = .003). In general, DCCR was well tolerated with 83.3% in the DCCR group experiencing a treatment-emergent adverse event and 73.8% in the placebo group (not significant). CONCLUSION: DCCR did not significantly improve hyperphagia in the primary analysis but did in participants with severe baseline hyperphagia and in the pre-COVID analysis. DCCR treatment was associated with significant improvements in body composition and clinician-reported outcomes.


Assuntos
COVID-19 , Síndrome de Prader-Willi , Humanos , Síndrome de Prader-Willi/complicações , Diazóxido/uso terapêutico , COVID-19/complicações , Obesidade/complicações , Hiperfagia/complicações
2.
Arch Dis Child ; 107(9): 790-795, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-34740879

RESUMO

Type 1 diabetes (T1D) is a chronic autoimmune disease of childhood affecting 1:500 children aged under 15 years, with around 25% presenting with life-threatening diabetic ketoacidosis (DKA). While first-degree relatives have the highest risk of T1D, more than 85% of children who develop T1D do not have a family history. Despite public health awareness campaigns, DKA rates have not fallen over the last decade. T1D has a long prodrome, and it is now possible to identify children who go on to develop T1D with a high degree of certainty. The reasons for identifying children presymptomatically include prevention of DKA and related morbidities and mortality, reducing the need for hospitalisation, time to provide emotional support and education to ensure a smooth transition to insulin treatment, and opportunities for new treatments to prevent or delay progression. Research studies of population-based screening strategies include using islet autoantibodies alone or in combination with genetic risk factors, both of which can be measured from a capillary sample. If found during screening, the presence of two or more islet autoantibodies has a high positive predictive value for future T1D in childhood (under 18 years), offering an opportunity for DKA prevention. However, a single time-point test will not identify all children who go on to develop T1D, and so combining with genetic risk factors for T1D may be an alternative approach. Here we discuss the pros and cons of T1D screening in the UK, the different strategies available, the knowledge gaps and why a T1D screening strategy is needed.


Assuntos
Diabetes Mellitus Tipo 1 , Cetoacidose Diabética , Adolescente , Autoanticorpos , Criança , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/genética , Cetoacidose Diabética/diagnóstico , Humanos , Programas de Rastreamento , Reino Unido/epidemiologia
3.
Nephrol Dial Transplant ; 35(6): 994-1001, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30307515

RESUMO

BACKGROUND: Alström syndrome (AS) is a rare autosomal recessive ciliopathy with a wide spectrum of clinical features, including cone-rod retinal dystrophy, neuronal deafness, severe insulin resistance and major organ failure. The characteristics of renal disease in the syndrome have not been systematically described. The aim of this study is to define the onset and progression of renal disease in AS. METHOD: Prospective observational cohort study. SETTING AND PARTICIPANTS: Thirty-two adult subjects from a national specialist clinic in UK and 86 subjects from an international AS registry were studied. OUTCOMES: First, an international registry cross-sectional study across all age groups to determine change in kidney function was performed. Secondly, a detailed assessment was carried out of adult AS patients with serial follow-up to determine incidence, aetiology and progression of renal disease. ANALYTICAL APPROACH: Generalized estimating equations were used to evaluate the relationship between age and estimated glomerular filtration rate (eGFR). Associations between patient factors and eGFR levels were then assessed in the adult AS cohort. RESULTS: The international registry study of the renal function of 118 subjects with AS (median age 21 years) showed a rapid decline with age, at an average of -16.7 and -10.9 mL/min/1.73 m2 per decade in males and females, respectively. In a UK national cohort of 32 patients with AS (median age 22 years), 20/32 (63%) had chronic kidney disease (CKD) Stage 3 or above based on eGFR <60 mL/min/1.73 m2 or evidence of albuminuria. Hyperuricaemia was noted in 25/32 (79%). Structural abnormalities such as nephrocalcinosis without hypercalcaemia and cysts were observed in 20/32 (63%) subjects. Lower urinary tract symptoms were frequent in 17/19 (70%) of AS patients. Histological evidence showed mixed tubulo-interstitial and glomerular disease. CONCLUSIONS: This is the first study to demonstrate that renal disease is the hallmark of AS, which starts early and progresses with age, leading to a high prevalence of advanced CKD at young age. AS should be considered in the differential diagnosis of rare genetic renal diseases.


Assuntos
Síndrome de Alstrom/complicações , Insuficiência Renal Crônica/patologia , Adulto , Estudos Transversais , Progressão da Doença , Feminino , Taxa de Filtração Glomerular , Humanos , Testes de Função Renal , Masculino , Fenótipo , Estudos Prospectivos , Insuficiência Renal Crônica/etiologia , Adulto Jovem
4.
Eur J Endocrinol ; 180(3): 213-221, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30566905

RESUMO

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.


Assuntos
Androgênios/sangue , Doenças do Sistema Endócrino/epidemiologia , Doenças do Sistema Endócrino/etiologia , Puberdade/sangue , Adolescente , Androstenodiona/sangue , Criança , Pré-Escolar , Desidroepiandrosterona/sangue , Sulfato de Desidroepiandrosterona/sangue , Doenças do Sistema Endócrino/sangue , Doenças do Sistema Endócrino/patologia , Feminino , Humanos , Masculino , Puberdade Precoce/sangue , Puberdade Precoce/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Maturidade Sexual/fisiologia , Testosterona/sangue
5.
J Pediatr Surg ; 53(2): 321-325, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29277467

RESUMO

AIM: Wolfram syndrome is a rare genetic defect in WFS1 or WSF2(CISD2). It includes diabetes mellitus and insipidis, sensorineural deafness, optic atrophy, but not bladder dysfunction. However, this has appeared a common finding in our national referral clinic, and we sought to quantify this problem. METHODS: Data were collected from a multidisciplinary team managing all Wolfram patients in the UK. The following was analyzed: age, date of non-invasive urodynamics (NIU), symptoms, bladder capacity, voided volume, post-void residual and uroflow pattern. Bladder capacity was given as percentage predicted bladder capacity (PBC). Bladders were divided into normal, overactive (OAB), and underactive (UAB). Symptoms, bladder behavior, and genotyping were correlated. Data were expressed as median (interquartile range). MAIN RESULTS: Forty patients with Wolfram syndrome were identified, and 38 underwent NIU. This showed normal bladder function (n=4), OAB (n=9), UAB (n=25). Symptoms were present in only 11 children. The different patterns of bladder behavior (OAB vs. normal vs. UAB) were significantly associated with different %PBC (36 (29-59)% vs. 105 (93-233)% vs. 100 (77.5-337)%; p<0.001), and percentage emptying (100 (80-100)% vs. 100 (87-100)% vs. 69 (48-93)%; p<0.05). There was no association of genotype, symptoms and bladder behavior. Patients with megacystis were older: [13.4 (9.7-16.1) vs. 15.4 (13.9-18.7) years; p<0.05). CONCLUSION: Bladder dysfunction is very common in Wolfram syndrome (~90%), but most children cope (symptoms ~30%). With time there is a significant progression to megacystis, which may represent an underlying neuropathic myogenic failure and is likely to require intervention in the future. LEVEL OF EVIDENCE: Level II (National cohort study of prognosis).


Assuntos
Doenças da Bexiga Urinária/etiologia , Síndrome de Wolfram/complicações , Adolescente , Criança , Pré-Escolar , Estudos de Coortes , Progressão da Doença , Feminino , Genótipo , Humanos , Masculino , Prevalência , Prognóstico , Bexiga Urinária/fisiopatologia , Doenças da Bexiga Urinária/epidemiologia , Doenças da Bexiga Urinária/fisiopatologia , Síndrome de Wolfram/diagnóstico , Síndrome de Wolfram/genética , Adulto Jovem
6.
Hum Mol Genet ; 24(3): 814-27, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25274773

RESUMO

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.


Assuntos
Cálcio/metabolismo , Insulina/metabolismo , Proteínas de Membrana/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Animais , Células COS , Linhagem Celular Tumoral , Células Cultivadas , Chlorocebus aethiops , Ditiotreitol/farmacologia , Regulação da Expressão Gênica , Humanos , Secreção de Insulina , Camundongos , Camundongos Knockout
7.
Hum Mol Genet ; 22(2): 203-17, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23035048

RESUMO

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.


Assuntos
Proteínas de Membrana/metabolismo , Subunidades Proteicas/metabolismo , ATPases Vacuolares Próton-Translocadoras/metabolismo , Apoptose/genética , Proteínas de Transporte , Ciclo Celular/genética , Linhagem Celular , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático , Regulação da Expressão Gênica , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Proteínas de Membrana/genética , Neurônios/metabolismo , Ligação Proteica , Domínios e Motivos de Interação entre Proteínas , Estabilidade Proteica , Transporte Proteico , Bombas de Próton/metabolismo , Vesículas Secretórias/metabolismo , ATPase Trocadora de Sódio-Potássio/química , ATPase Trocadora de Sódio-Potássio/metabolismo , ATPases Vacuolares Próton-Translocadoras/química
8.
Hypertension ; 61(1): 70-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23150507

RESUMO

High blood pressure (BP) is becoming increasingly common during childhood. Regular physical activity (PA) reduces BP in adults, but limited studies have reported inconsistent results among children. The aim of this study is to examine, for the first time, the cross-sectional and longitudinal associations between BP and objectively measured PA in young children of predominantly South Asian background. Data from the Birmingham healthy Eating and Active lifestyle for CHildren Study were analyzed. Five hundred seventy-four children, aged 5 to 7 years, underwent a series of measures at baseline and were followed up 2 years later. PA was objectively measured using accelerometry and converted to counts per minute (total PA, cpm), and time spent in moderate-vigorous PA (minutes per day). BP was measured by trained staff using standard protocols. Data were available for 512 children at baseline (mean age 6.5 years, range 5.4-7.8 years), and 427 of these children were followed up. Baseline total PA was inversely associated with diastolic BP at both baseline (adjusted regression coefficient: -0.75 mm Hg [95% CI -1.33 to -0.18] per 20 cpm) and follow-up (-0.74 mm Hg [95% CI -1.40 to -0.08]). All associations remained unchanged after further adjustment for weight status. This study strengthens evidence of a causal association between higher PA and lower BP in children as young as 5, independent of weight status. The results provide support for development of interventions to increase PA in young children.


Assuntos
Pressão Sanguínea/fisiologia , Exercício Físico/fisiologia , Atividade Motora/fisiologia , Criança , Pré-Escolar , Feminino , Humanos , Estudos Longitudinais , Masculino , Fatores de Risco , Instituições Acadêmicas , Estudantes
9.
Clin Endocrinol (Oxf) ; 73(5): 671-7, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20718767

RESUMO

OBJECTIVE: Nonsyndromic autosomal recessively inherited nongoitrous congenital hypothyroidism (CHNG) can be caused by mutations in TSHR, PAX8, TSHB and NKX2-5. We aimed to investigate mutational frequencies of these genes and genotype/phenotype correlations in consanguineous families with CHNG. DESIGN: Because consanguinity in individuals with a presumptive genetic condition is often an indicator of an autosomal recessive inheritance and allows firmer correlations to be established between genotype and phenotype, we planned to execute our study in consanguineous families. PATIENTS: Hundred and thirty-nine children with CHNG phenotype born to consanguineous families. MEASUREMENTS: First, we investigated cases for evidence of linkage to the four known CHNG genes by microsatellite marker analysis. Mutation analysis by direct sequencing was then performed in those cases in whom linkage to the relevant candidate gene could not be excluded. In addition, in silico analysis of the predicted structural effects of TSHR mutations was performed and related to the mutation-specific disease phenotype. RESULTS: Homozygous germline TSHR mutations were detected in six families (5%), but no mutations were detected in PAX8, TSHB and NKX2-5. Four of TSHR mutations had not previously been described. Genotype-phenotype correlations were established and found to be related to the predicted structural effects of the mutations. CONCLUSIONS: Known causative genes account for the development of CHNG only in a minority of cases, and our cohort should provide a powerful resource to identify novel causative genes and to delineate the extent of locus heterogeneity in autosomal recessively inherited CHNG.


Assuntos
Hipotireoidismo Congênito/genética , Receptores da Tireotropina/genética , Consanguinidade , Análise Mutacional de DNA , Proteína Homeobox Nkx-2.5 , Proteínas de Homeodomínio/genética , Humanos , Modelos Moleculares , Mutação , Fator de Transcrição PAX8 , Fatores de Transcrição Box Pareados/genética , Paquistão/etnologia , Linhagem , Tireotropina Subunidade beta/genética , Fatores de Transcrição/genética , Turquia , Reino Unido
10.
Pediatrics ; 124(3): e489-95, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19706580

RESUMO

BACKGROUND: The association between celiac disease (CD) and type 1 diabetes mellitus (DM) is recognized. Most cases of CD in patients with DM are reported to be asymptomatic. OBJECTIVES: The objectives of this study were to (1) compare and audit our practice with the published standards for screening for CD in children with DM, (2) characterize the children with DM and biopsy-confirmed CD, in terms of growth and gastrointestinal symptoms, and compare them with children with DM and negative celiac serology, and (3) document the effects of a gluten-free diet (GFD) after 1 year of gastrointestinal symptoms, growth, and insulin requirement. METHOD: We performed a retrospective case-note review of 22 children with DM, positive celiac serology +/- biopsy-confirmed CD, and 50 children with DM and negative celiac serology. RESULTS: Twenty-two children (3.9% of the total diabetic population) had positive celiac serology on screening, with 17 (3%) having biopsy-confirmed CD. Ninety-four percent of the children had standardized celiac serology testing. At diagnosis of CD, 13 of the 17 biopsy-positive children (76.4%) had > or =1 gastrointestinal symptom. The frequency of gastrointestinal symptoms in negative celiac serology diabetic children was 6% (3 of 50) (P < .0005). Symptoms resolved in all children after introduction of a GFD. A significant improvement in weight SD score (P = .008) and BMI SD score (P = .02) was noted in those compliant with a GFD after 1 year. CONCLUSIONS: Children with DM and CD have a higher frequency of gastrointestinal symptoms than their diabetic peers with negative celiac serology and are not truly asymptomatic. Institution of a GFD has a positive effect on nutritional status and symptom resolution in the short-term.


Assuntos
Doença Celíaca/complicações , Doença Celíaca/diagnóstico , Complicações do Diabetes/complicações , Gastroenteropatias/etiologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos
11.
Hum Mol Genet ; 17(2): 190-200, 2008 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17947299

RESUMO

Wolfram syndrome, an autosomal recessive disorder characterized by diabetes mellitus and optic atrophy, is caused by mutations in the WFS1 gene encoding an endoplasmic reticulum (ER) membrane protein, Wolframin. Although its precise functions are unknown, Wolframin deficiency increases ER stress, impairs cell cycle progression and affects calcium homeostasis. To gain further insight into its function and identify molecular partners, we used the WFS1-C-terminal domain as bait in a yeast two-hybrid screen with a human brain cDNA library. Na+/K+ ATPase beta1 subunit was identified as an interacting clone. We mapped the interaction to the WFS1 C-terminal and transmembrane domains, but not the N-terminal domain. Our mapping data suggest that the interaction most likely occurs in the ER. We confirmed the interaction by co-immunoprecipitation in mammalian cells and with endogenous proteins in JEG3 placental cells, neuroblastoma SKNAS and pancreatic MIN6 beta cells. Na+/K+ ATPase beta1 subunit expression was reduced in plasma membrane fractions of human WFS1 mutant fibroblasts and WFS1 knockdown MIN6 pancreatic beta-cells compared with wild-type cells; Na+/K+ ATPase alpha1 subunit expression was also reduced in WFS-depleted MIN6 beta cells. Induction of ER stress in wild-type cells only partly accounted for the reduced Na+/K+ ATPase beta1 subunit expression observed. We conclude that the interaction may be important for Na+/K+ ATPase beta1 subunit maturation; loss of this interaction may contribute to the pathology seen in Wolfram syndrome via reductions in sodium pump alpha1 and beta1 subunit expression in pancreatic beta-cells.


Assuntos
Retículo Endoplasmático/metabolismo , Proteínas de Membrana/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Encéfalo/metabolismo , Células COS , Linhagem Celular , Chlorocebus aethiops , DNA Complementar , Biblioteca Gênica , Humanos , Células Secretoras de Insulina/metabolismo , Técnicas do Sistema de Duplo-Híbrido , Síndrome de Wolfram
12.
PLoS Med ; 4(4): e118, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17407387

RESUMO

BACKGROUND: Macrosomia is associated with considerable neonatal and maternal morbidity. Factors that predict macrosomia are poorly understood. The increased rate of macrosomia in the offspring of pregnant women with diabetes and in congenital hyperinsulinaemia is mediated by increased foetal insulin secretion. We assessed the in utero and neonatal role of two key regulators of pancreatic insulin secretion by studying birthweight and the incidence of neonatal hypoglycaemia in patients with heterozygous mutations in the maturity-onset diabetes of the young (MODY) genes HNF4A (encoding HNF-4alpha) and HNF1A/TCF1 (encoding HNF-1alpha), and the effect of pancreatic deletion of Hnf4a on foetal and neonatal insulin secretion in mice. METHODS AND FINDINGS: We examined birthweight and hypoglycaemia in 108 patients from families with diabetes due to HNF4A mutations, and 134 patients from families with HNF1A mutations. Birthweight was increased by a median of 790 g in HNF4A-mutation carriers compared to non-mutation family members (p < 0.001); 56% (30/54) of HNF4A-mutation carriers were macrosomic compared with 13% (7/54) of non-mutation family members (p < 0.001). Transient hypoglycaemia was reported in 8/54 infants with heterozygous HNF4A mutations, but was reported in none of 54 non-mutation carriers (p = 0.003). There was documented hyperinsulinaemia in three cases. Birthweight and prevalence of neonatal hypoglycaemia were not increased in HNF1A-mutation carriers. Mice with pancreatic beta-cell deletion of Hnf4a had hyperinsulinaemia in utero and hyperinsulinaemic hypoglycaemia at birth. CONCLUSIONS: HNF4A mutations are associated with a considerable increase in birthweight and macrosomia, and are a novel cause of neonatal hypoglycaemia. This study establishes a key role for HNF4A in determining foetal birthweight, and uncovers an unanticipated feature of the natural history of HNF4A-deficient diabetes, with hyperinsulinaemia at birth evolving to decreased insulin secretion and diabetes later in life.


Assuntos
Hiperinsulinismo Congênito/genética , Macrossomia Fetal/genética , Fator 1-alfa Nuclear de Hepatócito/genética , Fator 4 Nuclear de Hepatócito/genética , Adolescente , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Animais , Peso ao Nascer , Glicemia/análise , Criança , Pré-Escolar , Hiperinsulinismo Congênito/embriologia , Hiperinsulinismo Congênito/fisiopatologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Sangue Fetal/química , Macrossomia Fetal/fisiopatologia , Fator 4 Nuclear de Hepatócito/deficiência , Fator 4 Nuclear de Hepatócito/fisiologia , Heterozigoto , Humanos , Hiperinsulinismo/congênito , Hiperinsulinismo/genética , Hipoglicemia/congênito , Hipoglicemia/genética , Lactente , Recém-Nascido , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Pessoa de Meia-Idade , Gravidez , Prevalência , Estudos Retrospectivos
13.
J Clin Endocrinol Metab ; 92(6): 2378-81, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17356046

RESUMO

CONTEXT: T(3) action in neurons is essential for brain development. Recent evidence indicates that monocarboxylate transporter 8 (MCT8) is important for neuronal T(3) uptake. Hemizygous mutations have been identified in the X-linked MCT8 gene in boys with severe psychomotor retardation and elevated serum T(3) levels. OBJECTIVE: The objective of this study was to determine the functional consequences of MCT8 mutations regarding transport of T(3). DESIGN: MCT8 function was studied in wild-type or mutant MCT8-transfected JEG3 cells by analyzing: 1) T(3) uptake, 2) T(3) metabolism in cells cotransfected with human type 3 deiodinase, 3) immunoblotting, and 4) immunocytochemistry. RESULTS: The mutations identified in MCT8 comprise four deletions (24.5 kb, 2.4 kb, 14 bp, and 3 bp), three missense mutations (Ala224Val, Arg271His, and Leu471Pro), a nonsense mutation (Arg245stop), and a splice site mutation (94 amino acid deletion). All tested mutants were inactive in uptake and metabolism assays, except MCT8 Arg271His, which showed approximately 20% activity vs. wild-type MCT8. CONCLUSION: These findings support the hypothesis that the severe psychomotor retardation and elevated serum T(3) levels in these patients are caused by inactivation of the MCT8 transporter, preventing action and metabolism of T(3) in central neurons.


Assuntos
Doenças Genéticas Ligadas ao Cromossomo X/genética , Deficiência Intelectual/genética , Transportadores de Ácidos Monocarboxílicos/genética , Transtornos Psicomotores/genética , Tri-Iodotironina/sangue , Linhagem Celular Tumoral , Códon sem Sentido , Deleção de Genes , Doenças Genéticas Ligadas ao Cromossomo X/metabolismo , Humanos , Deficiência Intelectual/metabolismo , Neurônios/metabolismo , Mutação Puntual , Transtornos Psicomotores/metabolismo , Sítios de Splice de RNA , Simportadores , Transfecção , Tri-Iodotironina/farmacocinética
14.
Diabetes ; 53(7): 1876-83, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15220213

RESUMO

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.


Assuntos
Diabetes Mellitus Tipo 1/genética , Nanismo/genética , Heterogeneidade Genética , Mutação , Osteocondrodisplasias/genética , eIF-2 Quinase/genética , Adolescente , Adulto , Criança , Pré-Escolar , Consanguinidade , Genes Recessivos , Humanos , Lactente , Mutação de Sentido Incorreto , Linhagem , Síndrome
16.
J Am Vet Med Assoc ; 217(12): 1812-1836, 2000 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36484630

RESUMO

Historically, veterinary medicine has made its greatest contributions in the public sector and in settings other than direct care of the individual patient. So why are so many of us unaware of our profession's achievements in this arena? My introduction to veterinary preventive medicine and public health was through military service. My obligation to serve a two-year doctor draft in the United States Air Force became an adventure for my family and me, rather than an unwelcome intrusion on my ultimate desire to return to private clinical practice. The operative words are private and clinical. Why was I unaware of the opportunities available to those of us educated in this discipline sometimes referred to as comparative medicine?

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA