Spinocerebellar ataxias

Abstract

-Spinocerebellar ataxias (SCAs) constitute a heterogeneous group of neurodegenerative diseases characterized by progressive cerebellar ataxia in association with some or all of the following conditions: ophthalmoplegia, pyramidal signs, movement disorders, pigmentary retinopathy, peripheral neuropathy, cognitive dysfunction and dementia. Objective: To carry out a clinical and genetic review of the main types of SCA. Method: The review was based on a search of the PUBMED and OMIM databases. Results: Thirty types of SCAs are currently known, and 16 genes associated with the disease have been identified. The most common types are SCA type 3, or Machado-Joseph disease, SCA type 10 and SCA types 7, 2, 1 and 6. SCAs are genotypically and phenotypically very heterogeneous. A clinical algorithm can be used to distinguish between the different types of SCAs. Conclusions: Detailed clinical neurological examination of SCA patients can be of great help when assessing them, and the information thus gained can be used in an algorithm to screen patients before molecular tests to investigate the correct etiology of the disease are requested.KEY WORDS: spinocerebellar ataxias, cerebellar atrophy, genotype, phenotype. Ataxias espinocerebelaresResumo -As ataxias espinocerebelares (AECs) compreendem um grupo heterogeneo de enfermidades neurodegenerativas, que se caracterizam pela presença de ataxia cerebelar progressiva, associada de forma variada com oftalmoplegia, sinais piramidais, distúrbios do movimento, retinopatia pigmentar, neuropatia periférica, disfunção cognitiva e demência. Objetivo: Realizar uma revisão clínico-genética dos principais tipos de AECs. Método: A revisão foi realizada através da pesquisa pelo sistema do PUBMED e do OMIM. Resultados: Na atualidade existem cerca de 30 tipos de AECs, com a descoberta de 16 genes. Os tipos mais comuns são a AEC tipo 3, ou doença de Machado-Joseph, a AEC tipo 10, e as AECs tipo 7, 2 1, e 6. As AECs apresentam grande heterogeneidade genotípica e fenotípica. Pode-se utilizar um algoritmo clínico para a pesquisa dos diferentes tipos de AECs. Conclusões: O exame clínico neurológico minucioso nos pacientes com AECs pode auxiliar sobremaneira na avaliação clínica destes pacientes, utilizando-se desta forma de um algoritmo, com os dados clínicos, que pode servir como um instrumento de triagem para a solicitação dos testes de genética molecular, para a correta investigação etiológica.

Ataxia espinocerebelar tipo 6: relato de caso

“…Gait imbalance, nystagmus, decreased muscle tone, dysarthria, vertigo, dysphagia, and dysphonia, and are frequently described symptoms in several studies 2,5,18 . We observed similar symptoms in our case.…”

“…Spinocerebellar ataxias (SCA) are a heterogeneous group of neurodegenerative diseases characterized by the presence of progressive cerebellar ataxia whose initial clinical manifestations include deterioration in balance and motor coordination, as well as ocular disorders [1][2][3] .…”

A newly identified locus for benign adult familial myoclonic epilepsy on chromosome 3q26.32-3q28

“…A striking example is spinocerebellar ataxia, which has at least 33 underlying genes. 11 Discovery of the fourth BAFME chromosomal region will facilitate the identification of the responsible gene. There are possible candidates considering their expression pattern and protein function.…”

Ataxia espinocerebelar tipo 7

“…They are characterized by the presence of progressive cerebellar ataxia, whose initial clinical manifestations are eye disorders and the deterioration of balance and coordination (1) .…”

“…The SCA type 7, whose identified chromosome is 3p located at 3p14, gene SCA 7, mutation CAG, ataxin-7 protein, has a high incidence in Sweden, Finland, United States and China (1,(4)(5)(6) .…”