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Abstract(s)
Introdução: O Transtorno do Espectro do Autismo corresponde a uma sĂndrome que contempla um dĂ©fice de comunicação e interação social, que cursa com padrĂ”es de comportamento repetitivos e restritivos caracterĂsticos. Pode haver atrasos/anormalidades no desenvolvimento, estando afetada/comprometida a linguagem. Considera-se que a prevalĂȘncia mundial tenha vindo a aumentar, com os estudos mais recentes a relatarem uma prevalĂȘncia de 1-3%. Embora esteja bem estabelecido que existe uma forte componente genĂ©tica associada a esta doença, a sua fisiopatologia ainda nĂŁo Ă© conhecida. Desta forma, o seu diagnĂłstico Ă© clĂnico e o tratamento multidisciplinar, tendo como principal objetivo a melhoria da comunicação e interação social e das capacidades cognitivas.
Objetivo: Efetuar um levantamento dos estudos mais recentes e principais resultados relativamente Ă investigação sobre a prevalĂȘncia e etiologia dos Transtornos do Espectro do Autismo nos Ășltimos 5 anos.
MĂ©todos: Nesta revisĂŁo de literatura foram utilizados como motores de busca a PubMED/MEDLINE, NCBI, Scielo, DARE e Elsevier para encontrar estudos publicados entre 2013 e Dezembro de 2018 relativos Ă prevalĂȘncia e etiologia dos Transtornos do Espectro do Autismo (TEA). Foram tambĂ©m consultadas publicaçÔes com data de publicação prĂ©via Ă janela estabelecida no Ăąmbito dos TEA, a sua etiologia, prevalĂȘncia, manifestaçÔes clĂnicas, diagnĂłstico e tratamento quando considerado necessĂĄrio. No final da anĂĄlise dos estudos, procedeu-se Ă sĂntese narrativa e discussĂŁo dos resultados encontrados.
DiscussĂŁo: Foi denotado no decorrer deste estudo uma tendĂȘncia de aumento global da prevalĂȘncia dos TEA, com valores estimados de prevalĂȘncia nos EUA de 2.5%, na Europa entre 2-3%, com restantes estudos a nĂvel mundial com valores bastante variĂĄveis. O rĂĄcio de TEA entre rapazes e raparigas Ă© de aproximadamente 4:1. Ă de realçar a forte componente familiar na etiologia deste transtorno, com valores de recorrĂȘncia entre irmĂŁos de 20-50%. Alguns sĂndromes genĂ©ticos tĂȘm sido associados aos TEA, com destaque para sĂndrome de Rett (61%), sĂndrome de Cohen (54%) e o sĂndrome de Cornelia de Lange (43%).
VĂĄrios estudos relatam um importante papel dos neurotransmissores na etiologia dos TEA, evidenciando que desequilĂbrios na sua função possam acometer processos celulares importantes, como a transmissĂŁo e plasticidade sinĂĄptica. Estudos evidenciam que vĂĄrias alteraçÔes genĂ©ticas estĂŁo associadas a genes que codificam proteĂnas essenciais Ă normal função sinĂĄptica, como molĂ©culas de adesĂŁo celular ou proteĂnas de scaffolding. Apesar desta forte componente genĂ©tica, estudos indicam como importante agente etiolĂłgico dos TEA a interação com fatores maternos como a idade, doenças ou estado nutricional, e fatores de exposição ambiental, com perĂodos distintos de exposição implicados (periconcepcional, prĂ©-natal, pĂłs-natal). ConclusĂ”es: A prevalĂȘncia dos TEA apresenta uma tendĂȘncia de subida a nĂvel mundial. Contudo, existe grande variabilidade de estimativas obtidas em vĂĄrias partes do mundo, possivelmente consequĂȘncia de diferentes mĂ©todos de estudo, meios de diagnĂłstico ou consciencialização.
EstĂĄ bem estabelecida a forte componente genĂ©tica dos Transtornos do Espectro do Autismo, contudo crĂȘ-se que o processo etiolĂłgico da doença esteja tambĂ©m sujeito Ă influĂȘncia de fatores ambientais e maternos. Considerando a provĂĄvel etiologia multifatorial dos TEA, os estudos dos fatores de risco devem dar prioridade a fatores de risco modificĂĄveis.
Devido Ă elevada heterogeneidade de mĂ©todos utilizados na investigação dos TEA, deve-se procurar uniformizar os mesmos de modo a serem obtidos resultados reprodutĂveis e mais coerentes.
Introduction: Autism Spectrum Disorder corresponds to a syndrome that includes a deficit in communication and social interaction, which is characterized by repetitive and restrictive patterns of behavior. There may be developmental delays or abnormalities, with a compromise to language. World prevalence is estimated to be increasing, with the most recent studies reporting a prevalence of 1-3%. Although it is well established that there is a strong genetic component associated with this disease, its pathophysiology is not yet known. Due to this, diagnosis is clinical and the treatment multidisciplinary, with the improvement of communication and social interaction and cognitive abilities as main therapeutic goal. Objective: To carry out a survey of the most recent studies and main results regarding research on the prevalence and etiology of Autism Spectrum Disorders in the last 5 years. Methods: In this literature review, PubMED / MEDLINE, NCBI, Scielo, DARE and Elsevier were used as search engines to find studies published between 2013 and December 2018 regarding the prevalence and etiology of Autism Spectrum Disorders (ASD). Publications with a date of publication prior to the window established in the scope of ASD, its etiology, prevalence, clinical manifestations, diagnosis and treatment were also consulted when considered necessary. At the end of the analysis of the studies, we proceeded to the narrative synthesis and discussion of the results found. Discussion: In the course of this study, a trend of rising global prevalence of ASD was observed, with estimated prevalence in the USA of 2.5%, in Europe between 2-3%, with other studies worldwide reporting very variable values. The ASD ratio for boys and girls is approximately 4:1. It is important to highlight the strong familial component in the etiology of this disorder, with recurrence values between siblings of 20-50%. Some genetic syndromes have been associated with ASD, with emphasis on Rett syndrome (61%), Cohen syndrome (54%) and Cornelia de Lange syndrome (43%). Several studies report an important role of neurotransmitters in the etiology of ASD, showing that imbalances in their function can affect important cellular processes such as synaptic plasticity and transmission. Studies show that several genetic alterations are associated with genes encoding proteins essential for normal synaptic function, such as cell adhesion molecules or scaffolding proteins. Despite the strong genetic component, studies indicate that the interaction with maternal factors and environmental exposure, with distinct periods of exposure (periconceptional, prenatal, and postnatal), may be implicated in ASD. Conclusions: The prevalence of ASD is rising worldwide. However, there is great variability of estimates obtained in various parts of the world, possibly due to different methods of study, diagnosis or awareness to the disease. The strong genetic component of Autism Spectrum Disorders is well established, but it is believed that the etiological process of the disease is also influenced by environmental and maternal factors. Considering the probable multifactorial etiology of ASD, risk factors studies should give priority to modifiable risk factors. Due to the high heterogeneity of methods used in the investigation of ASD, it should be sought to standardize them in order to obtain reproducible and more coherent results.
Introduction: Autism Spectrum Disorder corresponds to a syndrome that includes a deficit in communication and social interaction, which is characterized by repetitive and restrictive patterns of behavior. There may be developmental delays or abnormalities, with a compromise to language. World prevalence is estimated to be increasing, with the most recent studies reporting a prevalence of 1-3%. Although it is well established that there is a strong genetic component associated with this disease, its pathophysiology is not yet known. Due to this, diagnosis is clinical and the treatment multidisciplinary, with the improvement of communication and social interaction and cognitive abilities as main therapeutic goal. Objective: To carry out a survey of the most recent studies and main results regarding research on the prevalence and etiology of Autism Spectrum Disorders in the last 5 years. Methods: In this literature review, PubMED / MEDLINE, NCBI, Scielo, DARE and Elsevier were used as search engines to find studies published between 2013 and December 2018 regarding the prevalence and etiology of Autism Spectrum Disorders (ASD). Publications with a date of publication prior to the window established in the scope of ASD, its etiology, prevalence, clinical manifestations, diagnosis and treatment were also consulted when considered necessary. At the end of the analysis of the studies, we proceeded to the narrative synthesis and discussion of the results found. Discussion: In the course of this study, a trend of rising global prevalence of ASD was observed, with estimated prevalence in the USA of 2.5%, in Europe between 2-3%, with other studies worldwide reporting very variable values. The ASD ratio for boys and girls is approximately 4:1. It is important to highlight the strong familial component in the etiology of this disorder, with recurrence values between siblings of 20-50%. Some genetic syndromes have been associated with ASD, with emphasis on Rett syndrome (61%), Cohen syndrome (54%) and Cornelia de Lange syndrome (43%). Several studies report an important role of neurotransmitters in the etiology of ASD, showing that imbalances in their function can affect important cellular processes such as synaptic plasticity and transmission. Studies show that several genetic alterations are associated with genes encoding proteins essential for normal synaptic function, such as cell adhesion molecules or scaffolding proteins. Despite the strong genetic component, studies indicate that the interaction with maternal factors and environmental exposure, with distinct periods of exposure (periconceptional, prenatal, and postnatal), may be implicated in ASD. Conclusions: The prevalence of ASD is rising worldwide. However, there is great variability of estimates obtained in various parts of the world, possibly due to different methods of study, diagnosis or awareness to the disease. The strong genetic component of Autism Spectrum Disorders is well established, but it is believed that the etiological process of the disease is also influenced by environmental and maternal factors. Considering the probable multifactorial etiology of ASD, risk factors studies should give priority to modifiable risk factors. Due to the high heterogeneity of methods used in the investigation of ASD, it should be sought to standardize them in order to obtain reproducible and more coherent results.
Description
Keywords
Autismo Autista Etiologia PrevalĂȘncia Transtornos do Espectro do Autismo