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1.
N Engl J Med ; 375(3): 240-6, 2016 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-27468060

RESUMO

Patients with rare defects in the gene encoding proopiomelanocortin (POMC) have extreme early-onset obesity, hyperphagia, hypopigmentation, and hypocortisolism, resulting from the lack of the proopiomelanocortin-derived peptides melanocyte-stimulating hormone and corticotropin. In such patients, adrenal insufficiency must be treated with hydrocortisone early in life. No effective pharmacologic treatments have been available for the hyperphagia and obesity that characterize the condition. In this investigator-initiated, open-label study, two patients with proopiomelanocortin deficiency were treated with setmelanotide, a new melanocortin-4 receptor agonist. The patients had a sustainable reduction in hunger and substantial weight loss (51.0 kg after 42 weeks in Patient 1 and 20.5 kg after 12 weeks in Patient 2).


Assuntos
Hiperfagia/tratamento farmacológico , Erros Inatos do Metabolismo/tratamento farmacológico , Obesidade/tratamento farmacológico , Pró-Opiomelanocortina/deficiência , Receptor Tipo 4 de Melanocortina/agonistas , alfa-MSH/análogos & derivados , Adulto , Pressão Sanguínea , Feminino , Humanos , Hiperfagia/genética , Erros Inatos do Metabolismo/genética , Obesidade/genética , Fenótipo , Projetos Piloto , Pró-Opiomelanocortina/genética , Adulto Jovem , alfa-MSH/efeitos adversos , alfa-MSH/uso terapêutico
3.
Clin Endocrinol (Oxf) ; 86(4): 634-643, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28005277

RESUMO

OBJECTIVE: Rare congenital conditions with incongruence of chromosomal, gonadal and phenotypic sex have been classified as differences/disorders of sex development (DSD). Included in DSD are conditions with diverse genetic aetiology, varying levels of prenatal androgen effects, phenotypes and, subsequently, different medical treatments. Quality of life (QoL) and psychological well-being are indicators of successful psychosocial adaptation to the conditions. We sought to investigate the HRQoL and psychological well-being in this population. DESIGN: This multicentre clinical evaluation study was part of a German network related to DSD funded by the German Ministry of Science and Education (BMBF 2003 to 2007). METHODS: To assess health-related quality of life (HRQoL), we used the Short Form Health Survey (SF-36), and for psychological well-being, the Brief Symptom Inventory (BSI). Participants were classified into five groups: females with CAH, females with XY DSD conditions where there is a partial androgen effect (partial androgen insensitivity, mixed/partial gonadal dysgenesis, disorders of androgen biosynthesis), females with XY DSD without androgen effect (complete androgen insensitivity, complete gonadal dysgenesis), males with XY DSD, and individuals with DSD conditions and other gender. RESULTS: Participants included 110 adults with DSD (age range 17-62). We found a trend of lowered mental HRQoL and significant higher physical HRQoL for participants as compared to the norm. The high physical HRQoL especially applied to females with androgen effect and XY karyotype. Participants reported significant higher psychological distress compared to the norm. Forty-seven participants (42·7%) reported distress in a clinically relevant range on the BSI. CONCLUSIONS: Although we did not find significant impairments in overall HRQoL, participants reported significant impaired psychological well-being. Specialized interdisciplinary care should focus in particular on psychological issues to ensure good overall health and well-being.


Assuntos
Transtornos do Desenvolvimento Sexual/psicologia , Qualidade de Vida/psicologia , Adolescente , Adulto , Idoso , Androgênios , Transtorno 46,XY do Desenvolvimento Sexual , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Psicológico/etiologia , Inquéritos e Questionários , Adulto Jovem
4.
Eur J Pediatr ; 174(10): 1287-97, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25869494

RESUMO

UNLABELLED: Disorders/diversity of sex development (dsd) is an umbrella term for congenital conditions often diagnosed within childhood. As most parents are unprepared for this situation, psychological support (PsySupp) is recommended. The aim of this study was to analyse the extent to which parents express a need for PsySupp. Three hundred twenty-nine parents of children with dsd were included; 40.4 % of the parents indicated to have a need for PsySupp, only 50 % of this group received it adequately. The diagnoses partial gonadal dysgenesis, partial androgen insensitivity syndrome (pAIS) and disorders of androgen synthesis are associated with a high need for PsySupp in parents (54, 65, and 50 %). Sex assignment surgery neither reduced nor increased the need for PsySupp. Taking a picture, radiography, laparoscopy, gonadal biopsy, gonadectomy and hormonal puberty induction are associated with a high need for PsySupp. There was no association between the need for PsySupp and the parents' perception of the appearance of the genitalia. CONCLUSION: Having a child with dsd is associated with a high need for PsySupp in parents. In particular, parents of children with XY-dsd with androgen effects other than hypospadias expressed a high need of PsySupp. PsySupp for parents should be an obligatory part of interdisciplinary care to reduce fears and concerns. What is known • In parents, having a child with dsd provokes insecurities and fears. Hence, psychological support is recommended as part of the interdisciplinary care. What is new • This is the first study investigating the subjective need for psychological support in a large sample of parents of children with dsd in Germany. We present data on the subjective need for psychological support of the parents, related diagnoses and factors, which should be considered in psychological counselling.


Assuntos
Transtornos do Desenvolvimento Sexual/psicologia , Relações Pais-Filho , Pais/psicologia , Psicometria/métodos , Adolescente , Adulto , Criança , Transtornos do Desenvolvimento Sexual/reabilitação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Maturidade Sexual , Inquéritos e Questionários , Adulto Jovem
5.
J Med Genet ; 51(6): 375-87, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24714694

RESUMO

BACKGROUND: NKX2-1 encodes a transcription factor with large impact on the development of brain, lung and thyroid. Germline mutations of NKX2-1 can lead to dysfunction and malformations of these organs. Starting from the largest coherent collection of patients with a suspected phenotype to date, we systematically evaluated frequency, quality and spectrum of phenotypic consequences of NKX2-1 mutations. METHODS: After identifying mutations by Sanger sequencing and array CGH, we comprehensively reanalysed the phenotype of affected patients and their relatives. We employed electrophoretic mobility shift assay (EMSA) to detect alterations of NKX2-1 DNA binding. Gene expression was monitored by means of in situ hybridisation and compared with the expression level of MBIP, a candidate gene presumably involved in the disorders and closely located in close genomic proximity to NKX2-1. RESULTS: Within 101 index patients, we detected 17 point mutations and 10 deletions. Neurological symptoms were the most consistent finding (100%), followed by lung affection (78%) and thyroidal dysfunction (75%). Novel symptoms associated with NKX2-1 mutations comprise abnormal height, bouts of fever and cardiac septum defects. In contrast to previous reports, our data suggest that missense mutations in the homeodomain of NKX2-1 not necessarily modify its DNA binding capacity and that this specific type of mutations may be associated with mild pulmonary phenotypes such as asthma. Two deletions did not include NKX2-1, but MBIP, whose expression spatially and temporarily coincides with NKX2-1 in early murine development. CONCLUSIONS: The high incidence of NKX2-1 mutations strongly recommends the routine screen for mutations in patients with corresponding symptoms. However, this analysis should not be confined to the exonic sequence alone, but should take advantage of affordable NGS technology to expand the target to adjacent regulatory sequences and the NKX2-1 interactome in order to maximise the yield of this diagnostic effort.


Assuntos
Doenças Genéticas Inatas , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Adolescente , Criança , Pré-Escolar , Hibridização Genômica Comparativa , Variações do Número de Cópias de DNA/genética , Ensaio de Desvio de Mobilidade Eletroforética , Feminino , Deleção de Genes , Doenças Genéticas Inatas/genética , Doenças Genéticas Inatas/fisiopatologia , Humanos , Lactente , Recém-Nascido , Masculino , Fenótipo , Mutação Puntual/genética , Fator Nuclear 1 de Tireoide
6.
Clin Obes ; 14(3): e12659, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38602039

RESUMO

Nearly 90 clinicians and researchers from around the world attended the first IMPROVE 2022 International Meeting on Pathway-Related Obesity. Delegates attended in person or online from across Europe, Argentina and Israel to hear the latest scientific and clinical developments in hyperphagia and severe, early-onset obesity, and set out a vision of excellence for the future for improving the diagnosis, treatment, and care of patients with melanocortin-4 receptor (MC4R) pathway-related obesity. The meeting co-chair Peter Kühnen, Charité Universitätsmedizin Berlin, Germany, indicated that change was needed with the rapidly increasing prevalence of obesity and the associated complications to improve the understanding of the underlying mechanisms and acknowledge that monogenic forms of obesity can play an important role, providing insights that can be applied to a wider group of patients with obesity. World-leading experts presented the latest research and led discussions on the underlying science of obesity, diagnosis (including clinical and genetic approaches such as the role of defective MC4R signalling), and emerging clinical data and research with targeted pharmacological approaches. The aim of the meeting was to agree on the questions that needed to be addressed in future research and to ensure that optimised diagnostic work-up was used with new genetic testing tools becoming available. This should aid the planning of new evidence-based treatment strategies for the future, as explained by co-chair Martin Wabitsch, Ulm University Medical Center, Germany.


Assuntos
Obesidade , Receptor Tipo 4 de Melanocortina , Humanos , Obesidade/terapia , Receptor Tipo 4 de Melanocortina/genética , Receptor Tipo 4 de Melanocortina/metabolismo , Hiperfagia , Transdução de Sinais
7.
Orphanet J Rare Dis ; 18(1): 93, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37098531

RESUMO

PURPOSE: The transition process from paediatric/adolescent to adult medical care settings is of utmost importance for the future health of adolescents with chronic diseases and poses even more difficulties in the context of rare diseases (RDs). Paediatric care teams are challenged to deliver adolescent-appropriate information and structures. Here we present a structured transition pathway which is patient-focused and adoptable for different RDs. METHODS: The transition pathway for adolescents 16 years and older was developed and implemented as part of a multi-centre study in 10 university hospitals in Germany. Key elements of the pathway included: assessment of patients' disease-related knowledge and needs, training/educational and counselling sessions, a structured epicrisis and a transfer appointment jointly with the paediatric and adult specialist. Specific care coordinators from the participating university hospitals were in charge of organization and coordination of the transition process. RESULTS: Of a total of 292 patients, 286 completed the pathway. Deficits in disease-specific knowledge were present in more than 90% of participants. A need for genetic or socio-legal counselling was indicated by > 60%. A mean of 2.1 training sessions per patient were provided over a period of almost 1 year, followed by the transfer to adult care in 267 cases. Twelve patients remained in paediatric care as no adult health care specialist could be identified. Targeted training and counselling resulted in improved disease-specific knowledge and contributed to empowering of patients. CONCLUSION: The described transition pathway succeeds to improve health literacy in adolescents with RDs and can be implemented by paediatric care teams in any RD specialty. Patient empowerment was mainly achieved by individualized training and counselling.


Assuntos
Participação do Paciente , Doenças Raras , Humanos , Adolescente , Criança , Doença Crônica , Alemanha
8.
J Biol Chem ; 286(45): 39623-31, 2011 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-21940628

RESUMO

Interaction and cross-talk of G-protein-coupled receptors (GPCRs) are of considerable interest because an increasing number of examples implicate a profound functional and physiological relevance of homo- or hetero-oligomeric GPCRs. The ghrelin (growth hormone secretagogue receptor (GHSR)) and melanocortin-3 (MC3R) receptors are both known to have orexigenic effects on the hypothalamic control of body weight. Because in vitro studies indicate heterodimerization of GHSR and MC3R, we investigated their functional interplay. Combined in situ hybridization and immunohistochemistry indicated that the vast majority of GHSR-expressing neurons in the arcuate nucleus also express MC3R. In vitro coexpression of MC3R and GHSR promoted enhanced melanocortin-induced intracellular cAMP accumulation compared with activation of MC3R in the absence of GHSR. In contrast, agonist-independent basal signaling activity and ghrelin-induced signaling of GHSR were impaired, most likely due to interaction with MC3R. By taking advantage of naturally occurring GHSR mutations and an inverse agonist for GHSR, we demonstrate that the observed enhanced MC3R signaling capability depends directly on the basal activity of GHSR. In conclusion, we demonstrate a paradigm-shifting example of GPCR heterodimerization allowing for mutually opposite functional influence of two hypothalamic receptors controlling body weight. We found that the agonist-independent active conformation of one GPCR can determine the signaling modalities of another receptor in a heterodimer. Our discovery also implies that mutations within one of two interacting receptors might affect both receptors and different pathways simultaneously. These findings uncover mechanisms of important relevance for pharmacological targeting of GPCR in general and hypothalamic body weight regulation in particular.


Assuntos
Núcleo Arqueado do Hipotálamo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Multimerização Proteica/fisiologia , Receptor Tipo 3 de Melanocortina/metabolismo , Receptores de Grelina/metabolismo , Transdução de Sinais/fisiologia , Animais , Células COS , Chlorocebus aethiops , AMP Cíclico/genética , AMP Cíclico/metabolismo , Regulação da Expressão Gênica/fisiologia , Grelina/genética , Grelina/metabolismo , Células HEK293 , Humanos , Camundongos , Camundongos Knockout , Mutação , Proteínas do Tecido Nervoso/agonistas , Proteínas do Tecido Nervoso/genética , Receptor Tipo 3 de Melanocortina/agonistas , Receptor Tipo 3 de Melanocortina/genética , Receptores de Grelina/agonistas , Receptores de Grelina/genética
9.
Neuroendocrinology ; 95(4): 277-88, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22327910

RESUMO

The worldwide obesity epidemic is increasing, yet at this time, no long-acting and specific pharmaceutical therapies are available. Peripheral hormonal signals communicate metabolic status to the hypothalamus by activating their corresponding receptors in the arcuate nucleus (ARC). In this brain region, a variety of G protein-coupled receptors (GPCRs) are expressed that are potentially involved in weight regulation, but so far, the detailed function of most hypothalamic GPCRs is only partially understood. An important and underappreciated feature of GPCRs is the capacity for regulation via di- and heterodimerization. Increasing evidence implicates that heterodimerization of GPCRs results in profound functional consequences. Recently, we could demonstrate that interaction of the melanocortin 3 receptor (MC3R) and the growth hormone secretagogue receptor (GHSR)-1a results in a modulation of function in both receptors. Although the physiological role of GPCR-GPCR interaction in the hypothalamus is yet to be elucidated, this concept promises new avenues for investigation and understanding of hypothalamic functions dependent on GPCR signaling. Since GPCRs are important targets for drugs to combat many diseases, identification of heterodimers may be a prerequisite for highly specific drugs. Therefore, a detailed understanding of the mechanisms and their involvement in weight regulation is necessary. Fundamental to this understanding is the interplay of GPCR-GPCR in the hypothalamic nuclei in energy metabolism. In this review, we summarize the current knowledge on melanocortin receptors and GHSR-1a in hypothalamic weight regulation, especially as they pertain to possible drug targets. Furthermore, we include available evidence for the participation and significance of GPCR dimerization.


Assuntos
Núcleo Arqueado do Hipotálamo/metabolismo , Peso Corporal/fisiologia , Núcleo Hipotalâmico Paraventricular/metabolismo , Receptor Tipo 3 de Melanocortina/metabolismo , Receptor Tipo 4 de Melanocortina/metabolismo , Receptores de Grelina/metabolismo , Animais , Regulação do Apetite/fisiologia , Núcleo Arqueado do Hipotálamo/anatomia & histologia , Núcleo Arqueado do Hipotálamo/fisiologia , Humanos , Modelos Biológicos , Núcleo Hipotalâmico Paraventricular/anatomia & histologia , Núcleo Hipotalâmico Paraventricular/fisiologia , Multimerização Proteica/fisiologia , Receptor Tipo 3 de Melanocortina/fisiologia , Receptor Tipo 4 de Melanocortina/fisiologia , Receptores de Grelina/fisiologia
10.
Biochem J ; 439(2): 249-55, 2011 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-21726201

RESUMO

LAT2 (system L amino acid transporter 2) is composed of the subunits Slc7a8/Lat2 and Slc3a2/4F2hc. This transporter is highly expressed along the basolateral membranes of absorptive epithelia in kidney and small intestine, but is also abundant in the brain. Lat2 is an energy-independent exchanger of neutral amino acids, and was shown to transport thyroid hormones. We report in the present paper that targeted inactivation of Slc7a8 leads to increased urinary loss of small neutral amino acids. Development and growth of Slc7a8(-/-) mice appears normal, suggesting functional compensation of neutral amino acid transport by alternative transporters in kidney, intestine and placenta. Movement co-ordination is slightly impaired in mutant mice, although cerebellar development and structure remained inconspicuous. Circulating thyroid hormones, thyrotropin and thyroid hormone-responsive genes remained unchanged in Slc7a8(-/-) mice, possibly because of functional compensation by the thyroid hormone transporter Mct8 (monocarboxylate transporter 8), which is co-expressed in many cell types. The reason for the mild neurological phenotype remains unresolved.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/sangue , Sistema y+ de Transporte de Aminoácidos/metabolismo , Cadeias Leves da Proteína-1 Reguladora de Fusão/metabolismo , Transdução de Sinais , Hormônios Tireóideos/sangue , Sistema y+ de Transporte de Aminoácidos/genética , Animais , Sequência de Bases , Western Blotting , Encéfalo/crescimento & desenvolvimento , Primers do DNA , Cadeias Leves da Proteína-1 Reguladora de Fusão/genética , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Reação em Cadeia da Polimerase
11.
Dtsch Arztebl Int ; 119(27-28): 469-475, 2022 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-35635437

RESUMO

BACKGROUND: Patients with rare diseases often undergo a diagnostic odyssey that can last many years until the diagnosis is definitively established. To improve the diagnosis and treatment of these patients, the German National Task Force for Patients With Rare Diseases (Nationales Aktionsbündnis für Menschen mit Seltenen Erkrankungen, NAMSE) has recommended the creation of Rare Disease Centers (RDCs). METHODS: As part of the joint Translate-NAMSE project, sponsored by the G-BA Innovation Fund (G-BA, German Federal Joint Committee), we investigated the performance of RDCs in establishing the diagnosis of patients suspected to have a rare disease. The results of interdisciplinary case conferences and of exome diagnostic tests were analyzed in a prospective, multicenter observational study. RESULTS: A total of 5652 patients (of whom 3619 were under 18 years old, and 2033 were at least 18 years old) from 10 RDCs who did not yet have a definitive diagnosis of a rare disease were included in the study. On average, those who were under 18 years old had been symptomatic for 4.5 years without receiving a diagnosis in a standard care setting; the analogous figure for adult patients was 8.2 years. Over the course of this project (2017-2021), 1682 patients (30%) received a definitive diagnosis. 193 had a common disease, 88 had a psychosomatic disease (only in patients who were at least 18 years old), and 1401 had a rare disease. 14 850 case conferences were conducted. 1599 exome analyses led to 506 definitive genetic diagnoses (32%). CONCLUSION: A diagnostic evaluation with the aid of interdisciplinary case conferences and the opportunity for exome analysis can be of benefit to people with rare diseases who have not received a definitive diagnosis in a standard care setting. Further improvement of the diagnosis rate can come from whole-genome analysis and from the introduction of an international registry.


Assuntos
Doenças Raras , Adulto , Humanos , Adolescente , Doenças Raras/diagnóstico , Doenças Raras/genética , Doenças Raras/terapia , Estudos Prospectivos , Sequenciamento do Exoma , Sistema de Registros
12.
Cell Metab ; 3(2): 141-6, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16459315

RESUMO

Pro-opiomelanocortin (POMC) expressing neurons mediate the regulation of orexigenic drive by peripheral hormones such as leptin, cholecystokinin, ghrelin, and insulin. Most research effort has focused on alpha-melanocyte-stimulating hormone (alpha-MSH) as the predominant POMC-derived neuropeptide in the central regulation of human energy balance and body weight. Here we report a missense mutation within the coding region of the POMC-derived peptide beta-MSH (Y5C-beta-MSH) and its association with early-onset human obesity. In vitro and in vivo data as well as postmortem human brain studies indicate that the POMC-derived neuropeptide beta-MSH plays a critical role in the hypothalamic control of body weight in humans.


Assuntos
Peso Corporal/fisiologia , Metabolismo Energético/fisiologia , Homeostase/fisiologia , Mutação de Sentido Incorreto/genética , Obesidade/genética , beta-MSH/genética , Sequência de Aminoácidos , Sequência de Bases , Peso Corporal/genética , Metabolismo Energético/genética , Testes Genéticos , Homeostase/genética , Humanos , Hipotálamo/metabolismo , Imuno-Histoquímica , Dados de Sequência Molecular , Alinhamento de Sequência , Análise de Sequência de DNA
13.
J Biol Chem ; 285(36): 28054-63, 2010 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-20628049

RESUMO

Monocarboxylate transporter 8 (MCT8, SLC16A2) is a thyroid hormone (TH) transmembrane transport protein mutated in Allan-Herndon-Dudley syndrome, a severe X-linked psychomotor retardation. The neurological and endocrine phenotypes of patients deficient in MCT8 function underscore the physiological significance of carrier-mediated TH transmembrane transport. MCT8 belongs to the major facilitator superfamily of 12 transmembrane-spanning proteins and mediates energy-independent bidirectional transport of iodothyronines across the plasma membrane. Structural information is lacking for all TH transmembrane transporters. To gain insight into structure-function relations in TH transport, we chose human MCT8 as a paradigm. We systematically performed conventional and liquid chromatography-tandem mass spectrometry-based uptake measurements into MCT8-transfected cells using a large number of compounds structurally related to iodothyronines. We found that human MCT8 is specific for L-iodothyronines and requires at least one iodine atom per aromatic ring. Neither thyronamines, decarboxylated metabolites of iodothyronines, nor triiodothyroacetic acid and tetraiodothyroacetic acid, TH derivatives lacking both chiral center and amino group, are substrates for MCT8. The polyphenolic flavonoids naringenin and F21388, potent competitors for TH binding at transthyretin, did not inhibit T(3) transport, suggesting that MCT8 can discriminate its ligand better than transthyretin. Bioinformatic studies and a first molecular homology model of MCT8 suggested amino acids potentially involved in substrate interaction. Indeed, alanine mutation of either Arg(445) (helix 8) or Asp(498) (helix 10) abrogated T(3) transport activity of MCT8, supporting their predicted role in substrate recognition. The MCT8 model allows us to rationalize potential interactions of amino acids including those mutated in patients with Allan-Herndon-Dudley syndrome.


Assuntos
Transportadores de Ácidos Monocarboxílicos/química , Transportadores de Ácidos Monocarboxílicos/metabolismo , Hormônios Tireóideos/metabolismo , Sequência de Aminoácidos , Animais , Ligação Competitiva , Transporte Biológico , Humanos , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Transportadores de Ácidos Monocarboxílicos/genética , Mutagênese Sítio-Dirigida , Mutação , Conformação Proteica , Homologia de Sequência de Aminoácidos , Simportadores , Tri-Iodotironina Reversa/metabolismo
14.
N Engl J Med ; 358(17): 1811-8, 2008 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-18434651

RESUMO

DEHAL1 has been identified as the gene encoding iodotyrosine deiodinase in the thyroid, where it controls the reuse of iodide for thyroid hormone synthesis. We screened patients with hypothyroidism who had features suggestive of an iodotyrosine deiodinase defect for mutations in DEHAL1. Two missense mutations and a deletion of three base pairs were identified in four patients from three unrelated families; all the patients had a dramatic reduction of in vitro activity of iodotyrosine deiodinase. Patients had severe goitrous hypothyroidism, which was evident in infancy and childhood. Two patients had cognitive deficits due to late diagnosis and treatment. Thus, mutations in DEHAL1 led to a deficiency in iodotyrosine deiodinase in these patients. Because infants with DEHAL1 defects may have normal thyroid function at birth, they may be missed by neonatal screening programs for congenital hypothyroidism.


Assuntos
Bócio/genética , Hipotireoidismo/genética , Iodeto Peroxidase/genética , Mutação de Sentido Incorreto , Deleção de Sequência , Adulto , Sequência de Aminoácidos , Criança , Análise Mutacional de DNA , Feminino , Mutação da Fase de Leitura , Bócio/enzimologia , Homozigoto , Humanos , Hipotireoidismo/tratamento farmacológico , Hipotireoidismo/enzimologia , Iodeto Peroxidase/deficiência , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Monoiodotirosina/metabolismo , Fases de Leitura Aberta , Fenótipo , Reação em Cadeia da Polimerase
15.
J Neurosci ; 29(30): 9439-49, 2009 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-19641107

RESUMO

Thyroid hormone transport into cells requires plasma membrane transport proteins. Mutations in one of these, monocarboxylate transporter 8 (MCT8), have been identified as underlying cause for the Allan-Herndon-Dudley syndrome, an X-linked mental retardation in which the patients also present with abnormally high 3',3,5-triiodothyronine (T(3)) plasma levels. Mice deficient in Mct8 replicate the thyroid hormone abnormalities observed in the human condition. However, no neurological deficits have been described in mice lacking Mct8. Therefore, we subjected Mct8-deficient mice to a comprehensive immunohistochemical, neurological, and behavioral screen. Several behavioral abnormalities were found in the mutants. Interestingly, some of these behavioral changes are compatible with hypothyroidism, whereas others rather indicate hyperthyroidism. We thus hypothesized that neurons exclusively dependent on Mct8 are in a hypothyroid state, whereas neurons expressing other T(3) transporters become hyperthyroid, if they are exposed directly to the high plasma T(3). The majority of T(3) uptake in primary cortical neurons is mediated by Mct8, but pharmacological inhibition suggested functional expression of additional T(3) transporter classes. mRNAs encoding six T(3) transporters, including L-type amino acid transporters (LATs), were coexpressed with Mct8 in isolated neurons. We then demonstrated Lat2 expression in cultured neurons and throughout murine brain development. In contrast, LAT2 is expressed in microglia in the developing human brain during gestation, but not in neurons. We suggest that lack of functional complementation by alternative thyroid hormone transporters in developing human neurons precipitates the devastating neurodevelopmental phenotype in MCT8-deficient patients, whereas Mct8-deficient mouse neurons are functionally complemented by other transporters, for possibly Lat2.


Assuntos
Comportamento Animal , Proteínas de Membrana Transportadoras/deficiência , Deficiência Intelectual Ligada ao Cromossomo X/genética , Neurônios/fisiologia , Tri-Iodotironina/metabolismo , Sistema y+ de Transporte de Aminoácidos/metabolismo , Animais , Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Encéfalo/metabolismo , Células Cultivadas , Cadeias Leves da Proteína-1 Reguladora de Fusão/metabolismo , Humanos , Hipertireoidismo/fisiopatologia , Hipotireoidismo/fisiopatologia , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Camundongos , Camundongos Knockout , Microglia/metabolismo , Transportadores de Ácidos Monocarboxílicos , Testes Neuropsicológicos , Fenótipo , RNA Mensageiro/metabolismo , Simportadores , Síndrome
16.
J Inherit Metab Dis ; 32 Suppl 1: S355-9, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20033292

RESUMO

Glutaric aciduria type I (GA I), an autosomal-recessive deficiency of glutaryl-CoA-dehydrogenase, leads to encephalopathic crises resulting in irreversible neurological damage. As early diagnosis and implementation of appropriate treatment has significant benefit for these patients, GA I has been implemented in the extended newborn screening program in several countries. Screening parameter is glutarylcarnitine (C5DC) with its ratios. From 1 January 2005 until 31 December 2008, 173,846 newborns were examined by neonatal screening in our screening center. C5DC and/or at least three C5DC/acylcarnitine ratios were increased in 53 newborns (0.03%) and persisted in 11 infants after recall. GA I was not confirmed in any of these infants, but all 11 infants were suffering from renal insufficiency due to congenital (5/11) or acquired (6/11) renal disease. C5DC was shown to be significantly associated with renal affection and was significantly higher in infants with congenital renal insufficiency than in those with acquired renal insufficiency (p = 0.011). Creatinine correlated significantly with C5DC (p = 0.001) and all C5DC/acylcarnitine ratios, mainly with C5DC/(C8 + C10), C5DC/C0, C5DC/C2, C5DC/C4, and C5DC/C8 (for all: p = 0.001). Glutarylcarnitinemia associated with renal insufficiency has not yet been studied systematically. Renal damage in neonates might lead to disturbances in renal transporter systems of glutaric acid and its metabolites and a decreased excretion of C5DC, thus resulting in an increase of plasma C5DC. Therefore, newborns presenting with a positive screening indicating GA I may be considered not only to suffer from GA I but from renal insufficiency as well.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Encefalopatias Metabólicas/diagnóstico , Triagem Neonatal , Insuficiência Renal/diagnóstico , Erros Inatos do Metabolismo dos Aminoácidos/sangue , Encefalopatias Metabólicas/sangue , Carnitina/análogos & derivados , Carnitina/sangue , Diagnóstico Diferencial , Reações Falso-Positivas , Feminino , Alemanha , Glutaril-CoA Desidrogenase/sangue , Glutaril-CoA Desidrogenase/deficiência , Humanos , Recém-Nascido , Masculino , Insuficiência Renal/sangue , Insuficiência Renal/congênito
17.
J Clin Endocrinol Metab ; 104(4): 1079-1089, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30312418

RESUMO

CONTEXT: The α subunit of the stimulatory G protein (Gαs) links numerous receptors to adenylyl cyclase. Gαs, encoded by GNAS, is expressed predominantly from the maternal allele in certain tissues. Thus, maternal heterozygous loss-of-function mutations cause hormonal resistance, as in pseudohypoparathyroidism type Ia, whereas somatic gain-of-function mutations cause hormone-independent endocrine stimulation, as in McCune-Albright syndrome. OBJECTIVE: We report two unrelated boys presenting with a new combination of clinical findings that suggest both gain and loss of Gαs function. DESIGN AND SETTING: Clinical features were studied and sequencing of GNAS was performed. Signaling capacities of wild-type and mutant Gαs were determined in the presence of different G protein-coupled receptors (GPCRs) under basal and agonist-stimulated conditions. RESULTS: Both unrelated patients presented with unexplained hyponatremia in infancy, followed by severe early onset gonadotrophin-independent precocious puberty and skeletal abnormalities. An identical heterozygous de novo variant (c.1136T>G; p.F376V) was found on the maternal GNAS allele in both patients; this resulted in a clinical phenotype that differed from known Gαs-related diseases and suggested gain of function at the vasopressin 2 receptor (V2R) and lutropin/choriogonadotropin receptor (LHCGR), yet increased serum PTH concentrations indicative of impaired proximal tubular PTH1 receptor (PTH1R) function. In vitro studies demonstrated that Gαs-F376V enhanced ligand-independent signaling at the PTH1R, LHCGR, and V2R and, at the same time, blunted ligand-dependent responses. Structural homology modeling suggested mutation-induced modifications at the C-terminal α5 helix of Gαs that are relevant for interaction with GPCRs and signal transduction. CONCLUSIONS: The Gαs p.F376V mutation causes a previously unrecognized multisystem disorder.


Assuntos
Osso e Ossos/anormalidades , Cromograninas/genética , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Hiponatremia/genética , Puberdade Precoce/genética , Alelos , Substituição de Aminoácidos , Análise Mutacional de DNA , Feminino , Mutação com Ganho de Função , Heterozigoto , Humanos , Mutação com Perda de Função , Masculino , Herança Materna , Fenótipo , Pseudo-Hipoparatireoidismo
18.
Hum Mutat ; 29(1): 59-64, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17694559

RESUMO

Steroidogenic factor 1 (SF1, NR5A1) is a nuclear receptor that regulates multiple genes involved in adrenal and gonadal development, steroidogenesis, and the reproductive axis. Human mutations in SF1 were initially found in two 46,XY female patients with severe gonadal dysgenesis and primary adrenal failure. However, more recent case reports have suggested that heterozygous mutations in SF1 may also be found in patients with 46,XY partial gonadal dysgenesis and underandrogenization but normal adrenal function. We have analyzed the gene encoding SF1 (NR5A1) in a cohort of 27 patients with 46,XY disorders of sex development (DSD) from the German network of DSD. Heterozygous SF1 mutations were found in 5 out of 27 (18.5%) of cases. Four patients with SF1 mutations presented with the similar phenotype of mild gonadal dysgenesis, severe underandrogenization, and absent Müllerian structures. Of these, two patients harbored missense mutations within the DNA-binding region of SF1 (p.C33S, p.R84H), one patient had a nonsense mutation (p.Y138X) and one patient had a frameshift mutation (c.1277dupT) predicted to disrupt RNA stability or protein function. One additional patient ([c.424_427dupCCCA]+[p.G146A]) displayed a more marked phenotype of severe gonadal dysgenesis, normal female external genitalia, and Müllerian structures. Functional studies of the missense mutants (p.C33S, p.R84H) and of one nonsense mutant (p.Y138X) revealed impaired transcriptional activation of SF1-responsive target genes. To date, adrenal insufficiency has not occurred in any of the patients. Thus, SF1 mutations are a relatively frequent cause of 46,XY DSD in humans.


Assuntos
Disgenesia Gonadal 46 XY/genética , Mutação , Fator Esteroidogênico 1/genética , Adolescente , Glândulas Suprarrenais/metabolismo , Insuficiência Adrenal/diagnóstico , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Disgenesia Gonadal 46 XY/diagnóstico , Humanos , Fator Esteroidogênico 1/análise
19.
Eur Thyroid J ; 7(5): 225-237, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30374425

RESUMO

OBJECTIVES: Central hypothyroidism (CeH) is a rare form of hypothyroidism characterized by insufficient thyroid stimulation due to disturbed pituitary and/or hypothalamic functioning. Due to its origin and the whole clinical context, CeH represents a challenging condition in clinical practice as it is characterized by suboptimal accuracy of clinical and biochemical parameters for diagnosis and management. Since no expert consensus or guidance for this condition is currently available, a task force of experts received the commitment from the European Thyroid Association (ETA) to prepare this document based on the principles of clinical evidence. STUDY DESIGN: The task force started to work in February 2017 and after a careful selection of appropriate references (cohort studies, case reports, expert opinions), a preliminary presentation and live discussion during the 2017 ETA meeting, and several revision rounds, has prepared a list of recommendations to support the diagnosis and management of patients with CeH. RESULTS: Due to the particular challenges of this rare condition in the different ages, the target users of this guidance are pediatric and adult endocrinologists. Experts agreed on the need to recognize and treat overt CeH at all ages, whereas treatment of milder forms may be dispensable in the elderly (> 75 years). CONCLUSIONS: Despite the lack of randomized controlled clinical trials, the experts provide 34 recommendations supported by variable levels of strength that should improve the quality of life of the affected patients and reduce the metabolic and hormonal consequences of inadequate management.

20.
J Clin Endocrinol Metab ; 103(4): 1459-1469, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29325045

RESUMO

Context: The optimal levothyroxine (LT4) dose to treat congenital hypothyroidism (CH) remains unclear, with debate over whether higher starting doses (>10 µg/kg) are necessary and safe for a normal intelligence quotient (IQ). Objective: To examine psychomotor, metabolic, and quality of life (QoL) outcomes in patients with CH treated with a mean high initial LT4 dose. Design, settings, participants: A cross-sectional cohort study of patients with CH identified in the Berlin newborn screening program from 1979 to 2003; 76 patients with CH (mean age, 18 years; mean initial LT4 dose, 13.5 µg/kg) and 40 siblings completed the study. Main outcome measures: Psychomotor (Wechsler Intelligence Test, CNS Vital Signs), QoL (short form-36 Health Survey), anthropometric (body mass index, height), and metabolic (intima media thickness, laboratory parameters) outcomes were compared with those of healthy siblings. Mean values and percentage of episodes of elevated thyroxine (T4) and tri-jod-thyronin (T3) and suppressed thyrotropin (TSH) before age 2 years were analyzed. A meta-analysis of CH treatment studies was performed. Results: There were no significant differences in IQ, QoL, or other outcome measures in patients with CH compared with controls. Most T4 levels were high before age 2 years and during subsequent testing, but mean T3 and TSH levels remained normal. The meta-analysis showed a significant IQ difference in severe vs mild CH cases only when treatment started with an LT4 dose <10 µg/kg. Conclusions: High initial LT4 dosing was effective and safely achieved optimal cognitive development in patients with CH, including those severely affected. Supranormal T4 values during infancy were not associated with impaired IQ in adolescence.


Assuntos
Hipotireoidismo Congênito/tratamento farmacológico , Inteligência/efeitos dos fármacos , Tiroxina/uso terapêutico , Adolescente , Índice de Massa Corporal , Espessura Intima-Media Carotídea , Hipotireoidismo Congênito/sangue , Hipotireoidismo Congênito/psicologia , Estudos Transversais , Feminino , Humanos , Recém-Nascido , Masculino , Triagem Neonatal , Qualidade de Vida , Tiroxina/administração & dosagem , Tiroxina/sangue , Tri-Iodotironina/sangue , Escalas de Wechsler , Adulto Jovem
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