Aspectos neurobiológicos del Síndrome de Rett

El Síndrome de Rett es un trastorno monogénico ligado al cromosoma X, de carácter progresivo que afecta el neurodesarrollo principalmente de niñas durante las primeras etapas del ciclo vital. Su etiología se debe principalmente a las mutaciones de cambio de nucleótido único con pérdida de función del gen MECP2. Este gen codifica para la proteína del mismo nombre cuya principal función es actuar como un represor global de la transcripción mediante el reconocimiento de zonas metiladas de islas CpG y el reclutamiento de factores correpresores que modulan la expresión génica desacetilando histonas. Dentro de las principales alteraciones estructurales asociadas al síndrome se encuentran una morfología neuronal atípica con tamaño del soma neuronal y número de espinas dendríticas reducido, además de alteraciones neuroquímicas sobre todo en la señalización GABAérgica llevando a una desregulación entre señales excitatorias e inhibitorias, causando epilepsia. También se han descrito una serie de alteraciones metabólicas, oxidativas e inflamatorias. El tratamiento hasta ahora se ha enfocado más en buscar un alivio sintomático para las manifestaciones del síndrome pero se ha desarrollado recientemente terapia génica con el objetivo de tratar desde sus bases neurogenéticas la patología y evitar así el desarrollo alterado durante la niñez.

Rett Syndrome is a monogenic disorder linked to the X chromosome, of a progressive nature that affects neurodevelopment mainly in girls during the first stages of the life cycle. Its etiology is mainly due to loss-of-function single nucleotide change mutations of the MECP2 gene. This gene codes for the protein of the same name whose main function is to act as a global repressor of transcription through the recognition of methylated areas of CpG islands and the recruitment of corepressor factors that modulate gene expression by deacetylating histones. Among the main structural alterations associated with the syndrome are an atypical neuronal morphology with a size of the neuronal soma and a reduced number of dendritic spines, in addition to neurochemical alterations, especially in the GABAergic signal, leading to dysregulation between excitatory and inhibitory signals, causing epilepsy. A series of metabolic, oxidative, and inflammatory disorders have also been described. Until now, treatment has focused more on seeking symptomatic relief for the manifestations of the syndrome, but gene therapy has recently been developed with the aim of treating the pathology from its neurogenetic bases and thus avoiding altered development during childhood.

Mecanismos epigenéticos involucrados en la génesis del autismo / Epigenetic mechanisms involved in the genesis of autism

Resumen El autismo es un trastorno del neurodesarrollo de base neurobiológica, caracterizado por alteración en la interacción social y la comunicación, intereses restringidos y conductas estereotipadas. Se relaciona con trastornos en la sinaptogénesis y a multiples etiologías. La identificación de factores epigenéticos implicados en la génesis del autismo permiten una mejor comprensión de los mecanismos moleculares invo lucrados. Nuestro objetivo fue analizar los mecanismos epigenéticos relacionados al desarrollo del autismo, puntualizando entidades específicas y sus mecanismos fisiopatológicos. Analizamos de qué manera se rela cionan los trastornos en la metilación del ADN, la modificación de las histonas, la remodelación cromosómica y la regulación mediada por el ARN no codificantes con diversos síndromes genéticos como el frágil X, Rett, Mecp2patías, Phelam McDermid, tóxicos prenatales como el alcohol, ácido valproico, cannabis y ambientales cómo el estrés materno, todos ellos asociados a una mayor prevalencia de autismo. En conclusión, el recono cimiento de estos mecanismos abre nuevas posibilidades para la prevención, y probablemente en un futuro, en las entidades genéticas, permitirá el desarrollo de tratamientos específicos con modificaciones a la medida de cada entidad.

Abstract Autism is a neurobiological developmental disorder characterized by poor social interaction and communication, narrow interests, and stereotyped behaviors. It has been associated with disorders of synaptogenesis and multiple etiologies. The iden tification of the epigenetic factors involved in the genesis of autism allows a better understanding of the molecular mechanisms involved. Our objective was to analyze the epigenetic mechanisms related to the development of autism, specifying specific entities and their pathophysiological mechanisms. We analyze how DNA methylation disorders, histone modification, remodeling and chromosomal regulation mediated by non-coding RNA are related to various genetic syndromes such as fragile X, Rett, Pathias Mecp2, Phelam McDermid, prenatal toxins such as alcohol, valproic. acid, cannabis, and environmental toxins such as maternal stress, all associated with a higher prevalence of autism. In conclusion: the recognition of these mechanisms opens up new possibilities for preven tion and it is likely that, in genetic entities, it will allow the development of specific treatments with modifications tailored to each entity.

Síndrome de Rett: reporte de una nueva variante patogénica y revisión de la literatura a propósito de dos casos clínicos / Rett syndrome: report of a new pathogenic variant and review of the literature regarding two clinical cases

Resumen Introducción: El síndrome de Rett es un trastorno del neurodesarrollo con una frecuencia estimada de 1/10,000 recién nacidos vivos, el cual se presenta con un modelo de herencia ligado al cromosoma X. Las variantes patogénicas en el gen MECP2, el cual codifica para una proteína que participa en el desarrollo y la diferenciación del sistema nervioso central, causan este síndrome. El objetivo de este trabajo fue describir dos casos de síndrome de Rett, uno de ellos con una nueva variante del gen MECP2. Casos clínicos: El primer caso se trata de una paciente de 5 años con microcefalia y regresión del neurodesarrollo desde los 3 años. Clínicamente se diagnosticó de síndrome de Rett en estadio III. Se realizó la secuenciación del gen MECP2 y se identificó una variante probablemente patogénica en estado heterocigoto, c.606delC (p.Thr203Argfs*7), que no ha sido reportada previamente. El segundo caso es una paciente de 17 años, referida por discapacidad intelectual grave, que se encontró clínicamente en estadio IV. Se realizó la secuenciación de MECP2 y se identificó una variante patogénica [c.880C>T(p.Arg294*)] ya descrita previamente. Conclusiones: El diagnóstico clínico de síndrome de Rett se llevó a cabo con criterios establecidos. La confirmación diagnóstica fue mediante la secuenciación de MECP2. Para el correcto abordaje de los trastornos del neurodesarrollo es primordial conocer el fenotipo de síndrome de Rett, así como optar por el análisis molecular para la confirmación del diagnóstico. Los pacientes con síndrome de Rett requieren un seguimiento interdisciplinario para disminuir el impacto de las complicaciones.

Abstract Background: Rett syndrome is an X-linked neurodevelopmental disorder with an estimated frequency of 1/10,000 live births caused by hetereozygous pathogenic variants in the MECP2 gene, whose protein participates in the development and differentiation of the central nervous system. This study aimed to describe two cases with Rett syndrome diagnosis, one of them with a new variant of the MECP2 gene. Case reports: We first describe the case of a 5-year-old female with microcephaly and neurodevelopmental regression starting at 3 years old, clinically corresponding to stage III Rett syndrome. Sequencing of the MECP2 gene identified a heterozygous likely pathogenic variant [c.606delC (p.Thr203Argfs*7)] not reported previously. The second case is a 17-year-old female, referred due to severe intellectual disability, clinically found on stage IV. MECP2 sequencing was performed identifying a pathogenic variant previously described [c.880C> T (p.Arg294 *)]. Conclusions: Rett syndrome clinical diagnosis was carried out based on established criteria. MECP2 sequencing confirmed the diagnosis. For neurodevelopmental disorders approach, it is essential to know the phenotype of Rett syndrome and select the molecular tool for the diagnosis. Patients with Rett syndrome require interdisciplinary follow-up for reducing the impact of complications.

Graded and pan-neural disease phenotypes of Rett Syndrome linked with dosage of functional MeCP2

Rett syndrome (RTT) is a progressive neurodevelopmental disorder, mainly caused by mutations in MeCP2 and currently with no cure. We report here that neurons from R106W MeCP2 RTT human iPSCs as well as human embryonic stem cells after MeCP2 knockdown exhibit consistent and long-lasting impairment in maturation as indicated by impaired action potentials and passive membrane properties as well as reduced soma size and spine density. Moreover, RTT-inherent defects in neuronal maturation could be pan-neuronal and occurred in neurons with both dorsal and ventral forebrain features. Knockdown of MeCP2 led to more severe neuronal deficits as compared to RTT iPSC-derived neurons, which appeared to retain partial function. Strikingly, consistent deficits in nuclear size, dendritic complexity and circuitry-dependent spontaneous postsynaptic currents could only be observed in MeCP2 knockdown neurons but not RTT iPSC-derived neurons. Both neuron-intrinsic and circuitry-dependent deficits of MeCP2-deficient neurons could be fully or partially rescued by re-expression of wild type or T158M MeCP2, strengthening the dosage dependency of MeCP2 on disease phenotypes and also the partial function of the mutant. Our findings thus reveal stable neuronal maturation deficits and unexpectedly, graded sensitivities of neuron-inherent and neural transmission phenotypes towards the extent of MeCP2 deficiency, which is informative for future therapeutic development.

Factores de riesgo perinatal asociados al trastorno del espectro autista y al síndrome de Rett / Perinatal risk factors associated with autistic spectrum disorder and the Rett syndrome

Resumen El propósito de este proyecto fue identificar los factores de riesgo perinatal asociados al trastorno del espectro autista (TEA) y al síndrome de Rett y compararlos entre sí, estando enmarcado dentro de un estudio de tipo descriptivo. Para esta investigación se utilizó una unidad de análisis conformada por 421 historias clínicas, de las que 377 fueron de TEA y 44 de Rett, a las cuales se les aplicó un instrumento especializado en identificar factores de riesgo perinatales llamado Cuestionario Materno de Riesgo Perinatal (CMRP), con el que se encontró una gran prevalencia de niños nacidos por cesárea y que las ocupaciones de sus padres estaban relacionadas con los cuidados requeridos por el trastorno. Esta identificación de factores servirá para la toma de precauciones a nivel clínico médico y a nivel de prevención de los riesgos asociados al trastorno del espectro autista y el síndrome de Rett.

Abstract The purpose of this project was to identify the perinatal risk factors associated with Autism Spectrum Disorder (ASD) and Rett Syndrome and compare them to each other, being framed within a descriptive study; For this research, an analysis unit consisting of 421 medical records was used, of which 377 were from ASD and 44 from Rett, to which a specialized instrument was applied to identify perinatal risk factors called the Maternal Perinatal Risk Questionnaire (MPRQ ), which found a high prevalence of children born by caesarean section and that their parents' occupations were related to the care required by the disorder. This identification of factors will serve to take precautions at the medical clinical level and at the level of prevention of the risks associated with Autism Spectrum Disorder and Rett Syndrome.

Rett syndrome: the Brazilian contribution to the gene discovery / Síndrome de Rett: a contribuição brasileira para a descoberta do gene

ABSTRACT A brief history of the syndrome discovered by Andreas Rett is reported in this paper. Although having been described in 1966, the syndrome was only recognized by the international community after a report by Hagberg et al. in 1983. Soon, its importance was evident as a relatively frequent cause of severe encephalopathy among girls. From the beginning it was difficult to explain the absence of male patients and the almost total predominance of sporadic cases (99%), with very few familial cases. For these reasons, it was particularly difficult to investigate this condition until 1997, when a particular Brazilian family greatly helped in the final discovery of the gene, and in the clarification of its genetic mechanism. Brief references are made to the importance of the MECP2 gene, 18 years later, as well as to its role in synaptogenesis and future prospects.

RESUMO Uma breve história de uma síndrome neurológica descoberta por Andreas Rett é relatada neste artigo. Embora tenha ocorrido em 1966, a síndrome só foi reconhecida pela comunidade internacional após um relato de Hagberget al, em 1983. Logo, sua importância ficou evidente como causa relativamente frequente de encefalopatia grave entre as crianças do sexo feminino. Desde o início, foi difícil explicar a ausência de envolvimento de pacientes do sexo masculino e a quase absoluta preponderância de casos esporádicos (99%), com muitos poucos casos familiares. Por essas razões, foi difícil investigar essa condição até 1997, quando uma família brasileira em particular ajudou muito na descoberta final do gene e no esclarecimento de seu mecanismo genético. São feitas referências sucintas à importância do gene MECP2, dezoito anos depois, bem como ao seu papel na sinaptogênese e nas perspectivas futuras.

Síndrome de Rett: Análisis molecular del gen MECP2 en pacientes chilenas / Rett syndrome: MECP2 gene molecular analysis in Chilean patients

INTRODUCCIÓN: El síndrome de Rett (RTT) es un trastorno neurológico progresivo caracterizado por producir una regresión del desarrollo psicomotor en niñas previamente sanas. La mayoría de los casos son causados por variantes patogénicas en el gen MECP2, que codifica para la proteína methyl CpG- binding protein 2. OBJETIVO: Describir la frecuencia y el tipo de variantes patogénicas en MECP2 en mujeres chilenas con diagnóstico clínico de RTT. PACIENTES Y MÉTODO: Se invitó a participar en este estudio a mujeres chilenas con sospecha clínica de RTT. Se reunió información clínica mediante un cuestionario. Se analizaron variantes patogénicas en MECP2 mediante el método de secuenciación de Sanger y se utilizó Multiple Ligation-dependant Probe Amplification (MLPA) para la detección de duplicaciones y deleciones. RESULTADO: El estudio incluyó 14 pacientes con sospecha de RTT, de las cuales 8 (57%) pacientes tuvieron variantes patogénicas. Las restantes permanecen sin diagnóstico molecular. CONCLUSIÓN: Variantes patogénicas en MECP2 están presentes en pacientes chilenas con RTT. Es probable que haya otros genes o diagnósticos involucrados en las pacientes sin hallazgos en MECP2. A partir de este trabajo, el diagnóstico molecular está disponible en Chile.

INTRODUCTION: Rett syndrome (RTT) is a progressive neurological disorder characterized by regres sion of psychomotor development in previously healthy girls. Most cases are due to pathogenic va riants in the MECP2 gene which encodes for the methyl CpG-binding protein 2. OBJECTIVE: To des cribe the frequency and type of pathogenic variants in the MECP2 gene in Chilean female patients with clinical diagnosis of RTT. PATIENTS AND METHOD: Chilean women with clinical suspicion of RTT were invited to participate in the study. Clinical data were collected through a questionnaire. MECP2 pathogenic variants were analyzed by Sanger sequencing method and Multiplex Ligation-dependent Probe Amplification (MLPA) was used to detect duplications or deletions. RESULTS: The study in cluded 14 patients with suspected RTT, of which eight (57%) patients had pathogenic variants. The other patients remain without molecular diagnosis. CONCLUSIONS: Pathogenic variants in MECP2 are present in Chilean patients with RTT. It is likely that there are other genes or diagnoses involved in patients without MECP2 findings. As of this study, molecular diagnosis is available in Chile.

Positive effects of low dose IMPX977 on Rett syndrome related MeCP2 targeted-genes / 中草药·英文版

Objective: To investigate the effect of IMPX977 on MeCP2 targeted-genes and the feasibility of IMPX977 acting as a therapeutic candidate drug for Rett syndrome by genomewide transcription profiling. Methods: Rats’ cortex of control group, IMPX977-treated low-dose group (10 mg/kg), and IMPX977-treated high-dose group (30 mg/kg) were collected and RNA was extracted from the tissues. Then, RNA was subjected to RNA-sequencing. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) were used in functional enrichment analysis of differentially expressed genes. Results: Six MeCP2 targeted-genes were identified in the low/control categories, but not in the high/control categories. Conclusion: Low-dose treatment of IMPX977 (10 mg/kg) showed a positive effect on MeCP2 targeted-genes and it may serve as a drug candidate for Rett syndrome therapy with proper dosage.

Transtornos autísticos e estratégias promotoras de cuidados: revisão integrativa / Trastornos autísticos y estratégias promotoras de cuidados: revisión integradora / Autistic disorders and care promotion strategies: integrative review

Objetivo analisar a produção científica brasileira recente sobre Transtornos do Espectro Autista, identificando as estratégias de cuidados investigadas. Método revisão integrativa de literatura na base de dados LILACS e na biblioteca virtual SciELO. Foram selecionados artigos publicados entre 2011 e 2017, utilizando os descritores Transtorno Autístico, Síndrome de Asperger e Síndrome de Rett. Resultados vinte e quatro artigos foram caracterizados e analisados descritivamente, com exposição dos seus níveis de evidência. Doze estudos (50%) representavam pesquisas descritivas, nível de evidência VI. Onze estudos (45,8%) equivaliam a delineamento não experimental, nível de evidência IV. A estratégia mais estudada foi de diagnóstico e avaliação para a prática clínica, com aplicação de instrumentos já validados, seguida de avaliação de resultados terapêuticos. Conclusão a produção científica brasileira atual sobre Transtorno do Espectro Autista mostrou-se direcionada para o enfoque diagnóstico nas áreas de fonoaudiologia e psicologia.

Objetivo analizar la producción científica brasileña reciente sobre Trastornos del Espectro Autista, identificando las estrategias de cuidados investigadas. Método revisión integradora de literatura en la base de datos LILACS y en la biblioteca virtual SciELO. Fueron seleccionados artículos publicados entre 2011 y 2017, utilizando los descriptores Trastorno Autístico, Síndrome de Asperger y Síndrome de Rett. Resultados veinte y cuatro artículos fueron caracterizados y analizados descriptivamente, con exposición de sus niveles de evidencia. Doce estudios (50%) representaban investigaciones descriptivas, nivel de evidencia VI. Once estudios (45,8%) correspondían a diseño no experimental, nivel de evidencia IV. La estrategia más estudiada fue de diagnóstico y evaluación para la práctica clínica, con aplicación de instrumentos ya validados, seguida de evaluación de resultados terapéuticos. Conclusión la producción científica brasileña actual sobre Trastorno del Espectro Autista se mostró orientada al enfoque diagnóstico en las áreas de fonoaudiología y psicología.

Objective to analyze the recent Brazilian scientific production about Autism Spectrum Disorders, identifying the investigated care strategies. Method integrative literature review in the database LILACS and in the virtual library SciELO. Articles published between 2011 and 2017 were selected, using the descriptors Autistic Disorder, Asperger Syndrome and Rett Syndrome. Results twenty four articles were characterized and analyzed descriptively, and their levels of evidence were presented. Twelve studies (50%) represented descriptive research, level of evidence VI. Eleven studies (45.8%) had non-experimental designs, level of evidence IV. The most studied strategy was the diagnosis and evaluation for clinical practice, by applying validated tools, followed by the assessment of therapeutic outcomes. Conclusion current Brazilian scientific production about Autism Spectrum Disorder was focused on diagnosis in speech therapy and psychology.

Use of sugammadex in Rett syndrome: A case report

Rett syndrome (RS) is a neurodevelopmental disorder characterized by loss of cognitive, motor, and social skills, epilepsy, autistic behavior, abnormal airway patterns, gastroesophageal reflux, nutritional problems, and severe scoliosis. Although girls with RS show normal or near-normal growth until 6–8 months, they lose their skills after that. The anesthetic management of these patients requires care because of all these clinical features. Especially in the postoperative period, prolonged apnea is common and extubation is delayed. In this case report, the effect of using sugammadex was presented in a 16-year-old girl with RS. The patient's all bimaxillary teeth and 4 wisdom teeth were extracted under general anesthesia in one session with minimal surgical trauma and moderate bleeding. Sugammadex can be a rapid and reliable agent for the reversal of the neuromuscular block in neurodegenerative patients.

Novel FOXG1 mutation in a patient with congenital Rett variant: a case report / 天津医药

@#Objective To summarize the clinical features of children with congenital Rett variant caused by mutation of FOXG1 and provide the reference for the diagnosis and treatment of the disease. Methods The clinical data of a patient diagnosed as congenital Rett syndrome variant type were summarized. The DNA samples of peripheral blood from the patient and her parents were extracted. The targeted high-throughput sequencing technology was used to detect the sequence of targeted genes, which were associated with the symptoms of the child. Genes were then verified by sanger sequencing. Chromosomal microarray analysis was performed to detect chromosome microdeletions and microduplications. Results The child carried the c.506dupG, p.G169Gfs＊ 286 heterozygous mutations on FOXG1 gene, which located in 14q12, and her parents were wild-type. After querying the HGMD, Clinvar and dbSNP databases, we found that it was not reported. This case was clearly diagnosed as congenital Rett syndrome variant type. We confirmed that the mutation locus was a new mutation. Conclusion For cases with congenital Rett variant manifestations, FOXG1 gene mutation examination is recommended, and preventive treatment of partially predictable dysfunction should be carried out.

Updates on pathogenesis-related genes and diagnosis and treatment of Rett syndrome / 国际儿科学杂志

Rett syndrome ( RTT) is a devastating neurological disorder that is caused largely by muta-tions in the X-linked gene MECP2,other two genes associated with RTT are CDKL5 and FOXG1. RTT is one of the most common causes of mental retardation in girls,male cases are rare. Classical features of typical RTT in-clude losing acquired spoken language and hand skills,hand stereotypies,epilepsy and respiratory disorders. The diagnosis of RTT mainly depends on the clinical characteristics. Atpresent, it still lacks atargeted treatment. In this review,we summarize both the gene research,diagnosis and treatmentprogresses of RTT so as to improve the understanding of RTT.

Anesthetic management of a pediatric patient with Rett syndrome: A case report

Rett syndrome is a neurodevelopmental disease that almost always affects female patients. It is caused by mutations in MeCP2 in the majority of cases. Patients diagnosed with Rett syndrome may experience serious adverse events even with smaller amounts of medication for sedation and anesthesia. The major anesthetic concerns associated with Rett syndrome are lack of cooperation, abnormal continuous limb movements, abnormal respiratory control, difficult positioning secondary to scoliosis, and altered sensitivity to painful stimuli. Because of the risks caused by these problems, anesthesiologists should be aware of the specific anesthetic concerns of patients with Rett syndrome in order to safely administer anesthesia. Here, we describe the management of a pediatric patient diagnosed with Rett syndrome.

Síndrome de Rett: revisión de la literatura con primeros casos reportados en Colombia con caracterización clínica y molecular / Rett syndrome: review of the literature and first cases reported in Colombia with clinical characterization and molecular diagnosis

RESUMEN INTRODUCCIÓN: El síndrome de Rett es una condición neurológica severa y la segunda causa genética de retraso mental profundo en mujeres. Se genera por mutaciones en el gen MECP2 y es caracterizada por una pérdida de las ganancias psicomotoras, con una prevalencia general estimada de 1:10.000 niñas, según la extrapolación de algunos estudios europeos. OBJETIVOS: Realizar una revisión de la literatura sobre el síndrome de Rett y presentar una serie de casos diagnosticados en Colombia por clínica y prueba molecular. METODOLOGÍA: Se efectuó una búsqueda bibliográfica y de reportes de casos en 21 bases de datos internacionales, más de 14 revistas del área de la salud y dos motores de búsqueda generales entre 2014 y 2016. Los casos presentados fueron seleccionados de la consulta de genética médica realizada por los autores. HALLAZGOS: No se encontró ningún caso colombiano de síndrome de Rett, ni confirmado con prueba molecular en Latinoamérica. Se reporta así la primera serie de casos nacional y la mayor latinoamericana, conformada por siete pacientes con tipo clásico y tres atípicos, todas con diagnóstico molecular. CONCLUSIONES: Pese a tener una evolución clínica caracterizada, su baja prevalencia y amplio espectro clínico convierten al síndrome de Rett en un reto diagnóstico y terapéutico. La mutación c.749_750insT se reporta por primera vez, la c.473C>G por segunda en la literatura y la c.763C>T se presenta en dos pacientes con fenotipos totalmente distintos, lo que confirma la no correlación genotipo-fenotipo de la enfermedad.

SUMMARY INTRODUCTION: Rett Syndrome is a severe neurological condition and the second genetic cause of profound mental retardation in women. It is generated by mutations in the MECP2 gene and it is characterized by a loss of psychomotor gains, with an estimated overall prevalence of 1:10,000 girls, according to the extrapolation of some European studies. Objectives. To make a review of Rett Syndrome and to present a series of cases diagnosed in Colombia by clinical criteria and molecular tests. METHODOLOGY: We made a bibliographic research in 21 international databases, more than 14 health journals and two general search engines between 2014 and 2016. The cases presented were selected from the Medical Genetics consultation carried out by the authors. FINDINGS: No Colombian case of Rett Syndrome was found nor confirmed with molecular testing in Latin America. We report the first cases in Colombia and the largest in Latin America, consisting of seven patients with classic type and three with atypical type, all with molecular diagnosis. CONCLUSIONS: In spite of having a characterized clinical evolution, its low prevalence and broad clinical spectrum, make Rett Syndrome a diagnostic and therapeutic challenge. We report for the first time the mutation c.749_750insT, the c.473C> G for second time in the literature and the c.763C> T is presented in two patients with totally different phenotypes, confirming the non-correlation genotype-phenotype of the disease.

Comprehensive Evaluation on Effect of IMPX977 on Expression of Methyl-CpG-binding Protein 2 in Rats / 中草药·英文版

Objective To investigate the effect of IMPX977 on methyl-CpG-binding protein 2 (MeCP2) expression in rats. Methods Forty-eight SD rats were randomly divided into four groups: normal control group, olive oil (negative control, 5 mL/kg oil) group, and 10 mg/kg and 30 mg/kg IMPX977 administration groups. All rats were given corresponding dose of drugs each other day and administered orally for two weeks. Tissues including cortex and cerebellum were collected from rats to assay the expression of MeCP2 by quantitative RT-PCR and Western blotting. Results The IMPX977 supplement showed no significant effect on the body weight of rats. In normal rats, MeCP2 was highly expressed in cerebellum, cortex and hippocampus, and less expressed in heart, spleen and lung. In addition to male rats, compared with the control group, the expression of MeCP2 mRNA was significantly increased in cerebellum after 30 mg/kg IMPX977 treatment and contrarily, absolutely decreased in cortex of all treatment groups. Furthermore, in female rats MeCP2 mRNA was reduced in cortex of both olive oil and 30 mg/kg IMPX977 treatment groups compared with control group. Meanwhile, MeCP2 protein level was significantly elevated in cerebellum of treated male rats compared to the control group. In contrast to the control group, the expression of MeCP2 protein in both cerebellum and cortex of female rats in other three groups was increased. Conclusion IMPX977 treatment (10 mg/kg) may elevate the expression of MeCP2, which establishes experimental foundation for the further research on rat models of Rett syndrome.

General and oral characteristics of Rett syndrome: case report / Características gerais e orais da Síndrome de Rett: um relato de caso

Introdução: a Síndrome de Rett é uma doença neurodegenerativa que ocorre em indivíduos do sexo feminino. É a segunda causa mais frequente de deficiência mental em meninas e pode atingir diversos grupos raciais em todo o mundo. Objetivo: descrever as características gerais e orais de um indivíduo que está no terceiro estágio da doença. Relato de caso: paciente do sexo feminino portador da síndrome, com 7 anos e sete meses de idade, leucoderma, procedente de Vallo della Lucania, Salerno, Itália. O indivíduo encontra-se no terceiro estágio da síndrome, no qual são observadas características como a redução do comportamento autista, melhoras no contato visual, no sorriso e melhoras nas habilidades comunicativas. Durante o primeiro estágio da síndrome, dos seis aos dezoito meses de vida, o indivíduo se alimentava sozinho, porém ainda não andava. Já no segundo estágio a partir dos 18 meses de vida, começou a andar com a base alargada e com dois anos parou de falar. O exame genético molecular para síndrome de Rett acusou que houve uma mutação genética chamada "ad novo", ou seja, a mutação não foi de caráter hereditário. Conclusão: não há tratamento específico para a síndrome de Rett, apenas de suporte por meio da fisioterapia, hidroterapia, terapia ocupacional, musicoterapia, equoterapia, além de terapêuticas que tratam apenas alguns sintomas apresentados pela síndrome. O tratamento deve ser realizado de maneira multidisciplinar. O prognóstico consiste em acompanhar o paciente por toda a vida, tratando os sintomas por ele apresentados.(AU)

Introduction: Rett syndrome is a neurodegenerative disease that affects females of all races worldwide. It is the second most frequent cause of mental disability in girls. Objective: To describe the general and oral characteristics at stage three. Case report: A girl aged seven years and seven months, leukoderma, coming from Vallo della Lucania, Salerno, Italy was at the stage three of Rett syndrome. At the first stage, from six to eighteen months of life, the girl ate by herself, but she did not walk. At the second stage, from eighteen months of life, she started the ataxic gait and stopped talking. At the third stage, she had the reduction of the autist behavior, improved the eye contact, smile and communicative abilities. The genetic examination revealed de novo mutation, that is, without inheritance. Conclusion: Rett syndrome lacks specific treatment. Adjuvant therapies include physiotherapy, hydrotherapy, occupational therapy, music therapy, equine therapy, as well as therapies to treat some symptoms. A multidisciplinary treatment is required. The prognosis consists of following-up the individual throughout life, treating the symptoms.(AU)

Síndrome de Rett: uma revisão da literatura / Rett Syndrome: a review of the literature

Síndrome de Rett (SR) é uma desordem neurológica severa do desenvovimento, e a sua incidência é de 1:10.000 nascimentos do sexo feminino, uma das causas genéticas mais comuns de atraso mental severo em mulheres. O desenvolvimento é aparentemente normal nos primeiros seis a 18 meses de vida até que ocorre a regressão das habilidades cognitivas, sociais e motoras. A progressão e severidade da desordem são avaliadas de forma clássica e divididas em estágio I, de estagnação precoce, estágio II, rapidamente destrutivo, estágio III, pseudo estacionária, e estágio IV, de deterioração motora tardia. As mutações no gene ligado ao X metil-CpG de ligação a proteína 2 (MECP2) está presente na maioria das pacientes com a SR. O tratamento fisioterapêutico é bastante eficaz, visto que melhora ou mantém as capacidades funcionais, funções sensoriais e motoras na SR. Benefícios estes que causam grande impacto na qualidade de vida desses indivíduos com deficiências severas.

Rett syndrome (RS) is a severe neurological developmental disorder, and its incidence is 1: 10,000 female births, one of the most common genetic causes of severe mental retardation in females. The development is apparently normal in the first six to 18 months of life until regression occurs cognitive, social and motor skills. The progression and severity of the disorder are assessed and classically divided into stage I, early stagnation, stage II, rapidly destructive, stage III, stationary pseudo, and stage IV, the late motor deterioration. Mutations in the X-linked gene 2 protein binding of methyl-CpG (MECP2) is present in most patients with MR. The physical therapy is quite effective, as it improves or maintains the funcional, sensory and motor functions in SR. These benefits that greatly impact quality of life of individuals with severe disabilities.

Functional Profiling of Human MeCP2 by Automated Data Comparison Analysis and Computerized Expression Pathway Modeling / 대한의료정보학회지

OBJECTIVES: Methyl-CpG binding protein 2 (MeCP2) is a ubiquitous epigenetic factor that represses gene expression by modifying chromatin. Mutations in the MeCP2 gene cause Rett syndrome, a progressive neurodevelopmental disorder. Recent studies also have shown that MeCP2 plays a role in carcinogenesis. Specifically, functional ablation of MeCP2 suppresses cell growth and leads to the proliferation of cancer cells. However, MeCP2's function in adult tissues remains poorly understood. We utilized a weight matrix-based comparison software to identify transcription factor binding site (TFBS) of MeCP2-regulated genes, which were recognized by cDNA microarray analysis. METHODS: MeCP2 expression was silenced using annealed siRNA in HEK293 cells, and then a cDNA microarray analysis was performed. Functional analysis was carried out, and transcriptional levels in target genes regulated by MeCP2 were investigated. TFBS analysis was done within genes selected by the cDNA microarray analysis, using a weight matrix-based program and the TRANSFAC 6.0 database. RESULTS: Among the differentially expressed genes with a change in expression greater than two-fold, 189 genes were up-regulated and 91 genes were down-regulated. Genes related to apoptosis and cell proliferation (JUN, FOSL2, CYR61, SKIL, ATF3, BMABI, BMPR2, RERE, and FALZ) were highly up-regulated. Genes with anti-apoptotic and anti-proliferative functions (HNRPA0, HIS1, and FOXC1) were down-regulated. Using TFBS analysis within putative promoters of novel candidate target genes of MeCP2, disease-related transcription factors were identified. CONCLUSIONS: The present results provide insights into the new target genes regulated by MeCP2 under epigenetic control. This information will be valuable for further studies aimed at clarifying the pathogenesis of Rett syndrome and neoplastic diseases.

Functional Profiling of Human MeCP2 by Automated Data Comparison Analysis and Computerized Expression Pathway Modeling / 대한의료정보학회지

OBJECTIVES: Methyl-CpG binding protein 2 (MeCP2) is a ubiquitous epigenetic factor that represses gene expression by modifying chromatin. Mutations in the MeCP2 gene cause Rett syndrome, a progressive neurodevelopmental disorder. Recent studies also have shown that MeCP2 plays a role in carcinogenesis. Specifically, functional ablation of MeCP2 suppresses cell growth and leads to the proliferation of cancer cells. However, MeCP2's function in adult tissues remains poorly understood. We utilized a weight matrix-based comparison software to identify transcription factor binding site (TFBS) of MeCP2-regulated genes, which were recognized by cDNA microarray analysis. METHODS: MeCP2 expression was silenced using annealed siRNA in HEK293 cells, and then a cDNA microarray analysis was performed. Functional analysis was carried out, and transcriptional levels in target genes regulated by MeCP2 were investigated. TFBS analysis was done within genes selected by the cDNA microarray analysis, using a weight matrix-based program and the TRANSFAC 6.0 database. RESULTS: Among the differentially expressed genes with a change in expression greater than two-fold, 189 genes were up-regulated and 91 genes were down-regulated. Genes related to apoptosis and cell proliferation (JUN, FOSL2, CYR61, SKIL, ATF3, BMABI, BMPR2, RERE, and FALZ) were highly up-regulated. Genes with anti-apoptotic and anti-proliferative functions (HNRPA0, HIS1, and FOXC1) were down-regulated. Using TFBS analysis within putative promoters of novel candidate target genes of MeCP2, disease-related transcription factors were identified. CONCLUSIONS: The present results provide insights into the new target genes regulated by MeCP2 under epigenetic control. This information will be valuable for further studies aimed at clarifying the pathogenesis of Rett syndrome and neoplastic diseases.

Bases moleculares del síndrome de Rett, una mirada actual / Molecular basis of Rett syndrome: A current look

El síndrome de Rett (SR) es un trastorno del neurodesarrollo que afecta casi exclusivamente a niñas y cursa secundariamente con autismo. Es poco frecuente y consta de 5 formas clínicas, una clásica y el resto atípicas que comprometen de manera general la habilidad manual, el lenguaje y la motricidad amplia unida a la aparición de estereotipias y epilepsia precoz. Con el objetivo de actualizar la información sobre SR, se aplicaron los descriptores de búsqueda Síndrome de Rett, genes y «Síndrome de Rett¼, «Rett Syndrome gene¼, «Rett Syndrome¼, «Rett Syndrome gene therapy¼ y «Rett Syndrome review¼. Se investigó en los archivos digitales PubMed, Hinari, SCIELO y Medline, y se consultaron los sitios web OMIM, ORPHANET, GeneMap, Genetests, Proteins y Gene, entre otros. Entre 1.348 artículos se seleccionaron 42, los cuales reportan 3 genes causantes del síndrome: MECP2, CDKL5 y FOXG. El gen MECP2 está mutado en el 80% de los pacientes con SR clásico así como en el 40% de los afectados con alguna de sus formas atípicas. El SR con epilepsia precoz y la variante congénita se deben fundamentalmente a variaciones en los genes CDKL5 y FOXG1 respectivamente. Conclusiones: El diagnóstico del SR se basa en criterios clínicos, sin embargo, los avances en la biología molecular y en la genética en particular han abierto el abanico de posibilidades diagnósticas a las diferentes formas clínicas que antes quedaban sin clasificar, a la vez que el análisis molecular permite confirmar el criterio clínico y aportar información en cuanto al pronóstico del paciente.

Rett syndrome (RS) is a neurodevelopmental disorder that exclusively affects girls, and occurs along with autism. It is very uncommon, and has five distinct forms, one classic and the others atypical, which generally compromise manual skills, language, and mobility, and widely associated with the appearance of stereotypy and early epilepsy. With the aim of updating the information about RS, a search was performed in the computer data bases of PubMed, Hinari, SCIELO and Medline, as well as consulting other web sites including OMIM, ORPHANET, GeneMap, Genetests, Proteins and Gene, using the descriptors "Síndrome de Rett", "genes y Síndrome de Rett", "Rett Syndrome gene", "Rett Syndrome", "Rett Syndrome gene therapy", and "Rett Syndrome review". Of the 1,348 articles found, 42 articles were selected, which reported 3 genes causing the syndrome: MECP2, CDKL5 and FOXG. The MECP2 gene is mutated in 80% of patients with classic RS, as well as in 40% of those affected by any of its atypical forms. RS with early epilepsy and the congenital variant are mainly due to variations in the CDKL5 and FOXG1 genes, respectively. Conclusions: The diagnosis of RS is based on clinical criteria. However, the advances in molecular biology and genetics have opened a wide range of possibilities for diagnosing the different clinical forms that could not be classified before. Molecular analysis can help confirm the clinical criteria and provided information as regards the prognosis of the patient.