Evidence and practices of the use of next generation sequencing in patients with undiagnosed autosomal dominant cerebellar ataxias: a review / Evidências e práticas do uso do sequenciamento de nova geração em pacientes com ataxias cerebelares autossômicas dominantes não diagnosticadas: uma revisão

ABSTRACT Autosomal dominant cerebellar ataxias (ADCA) are heterogeneous diseases with a highly variable phenotype and genotype. They can be divided into episodic ataxia and spinocerebellar ataxia (SCA); the latter is considered the prototype of the ADCA. Most of the ADCA are caused by polyglutamine expansions, mainly SCA 1, 2, 3, 6, 7, 17 and Dentatorubral-pallidoluysian atrophy (DRPLA). However, 30% of patients remain undiagnosed after testing for these most common SCA. Recently, several studies have demonstrated that the new generation of sequencing methods are useful for the diagnose of these patients. This review focus on searching evidence on the literature, its usefulness in clinical practice and future perspectives.

RESUMO As ataxias cerebelares autossômicas dominantes (ACAD) são doenças heterogêneas com fenótipo e genótipo altamente variáveis. Podem ser divididas em ataxia episódica e ataxia espinocerebelar (SCA), sendo este último considerado o protótipo do ACAD. A maior parte das ACAD são causadas por expansões de poliglutaminas, principalmente SCA 1, 2, 3, 6, 7, 17 e atrofia dentatorubro-palidoluisiana (DRPLA). No entanto, 30% dos pacientes permanecem sem diagnóstico após o teste para essas SCA mais comuns. Recentemente, vários estudos têm demonstrado que a nova geração de métodos de sequenciamento são ferramentas úteis para o diagnóstico desses pacientes. Esta é uma revisão sistemática da literatura, com foco em sua utilidade na prática clínica e em perspectivas futuras.

Obsessive-compulsive disorder in a patient with SCA type 1 / Transtorno obsessivo compulsivo em um paciente com SCA tipo 1

For many years, the cerebellum was thought to be only responsible for balance, movement, planning and execution. Nowadays, it is well accepted that most cerebellar connections are involved in non-motor functions. Herein, we provide a case report in which a 27-year-old Brazilian male, diagnosed with Obsessive-Compulsive Disorder (OCD), has demonstrated cerebellar features that could be connected to Spinocerebellar ataxia type 1 (SCA-1), an autosomal dominant polyglutamine neurodegenerative disorder that had been previously ruled out. Since obsessive compulsive symptoms (OCS) are known to correlate with alterations in the cortico-striato-thalamo-cortical circuitry, we propose a possible association between OCS and SCA onset.

Durante muitos anos, o cerebelo foi considerado responsável exclusivamente pelo controle das funções de equilíbrio, movimento, planejamento e execução. Atualmente, já está consagrada a participação das conexões cerebelares em funções não-motoras. Apresentamos um relato de caso de um paciente de 27 anos de idade, diagnosticado com Transtorno Obsessivo-Compulsivo (TOC). O paciente apresentava sintomas cerebelares compatíveis com o diagnóstico de ataxia espinocerebelar tipo 1 (SCA-1), um distúrbio da poliglutamina, autossômico dominante neurodegenerativo, que havia sido previamente descartado. Como os sintomas obsessivos compulsivos (SOC) são conhecidos por correlacionar-se com alterações nos circuitos cortico-estriato-tálamo-cortical, propomos uma possível associação entre o SOC e o início da SCA.

Ataxia espinocerebelar do tipo 2: aspectos clínicos, qualidade de vida, depressão e ansiedade em cinco portadores de uma família / Spinocerebellar ataxia type 2: clinical, quality life, depression and anxiety in five members of same family

A ataxia espinocerebelar do tipo 2 (SCA2) é uma das ataxias cerebelares autossômicas dominantes mais frequentes, resultando em significativo prejuízo funcional progressivo na vida dos portadores. Estudos relacionados à SCA2 no Brasil são escassos. O objetivo deste estudo foi descrever aspectos clínicos de cinco membros de uma mesma família portadores de SCA2 e correlacioná-los com qualidade de vida, depressão e ansiedade. Aspectos clínicos avaliados incluíram idade de início, tempo da doença e aplicação da Escala Cooperativa Internacional para Graduação de Ataxia (ICARS), além de avaliação de neuroimagem e tipos de tratamento. Para avaliação da ansiedade e depressão, foi utilizada a Escala de Beck, e para a qualidade de vida, a SF-36. Em relação ao estudo genético, foi avaliado o número de repetições do trinucleotídeo CAG. Análise estatística descritiva e inferencial foi realizada. As idades de início variaram de 14 a 30 anos e o tempo de doença variou de 8 a 27. A maior expansão de trinucleotídeo CAG foi 48, relacionada com a menor idade de início e pior ataxia. A caracterização clínica obtida por meio da ICARS foi variável e todos apresentaram diminuição da qualidade de vida, especialmente nos domínios: limitação por aspectos físicos, aspectos emocionais e capacidade funcional. A pontuação obtida pela Escala de Beck de depressão e ansiedade foi baixa em todos os indivíduos. Houve correlação, mas sem significância estatística, entre tempo de doença e capacidade funcional e entre tempo de doença e ICARS. Os indivíduos com SCA2 analisados neste estudo apresentaram achados clínicos variados e comprometimento das habilidades motoras e da qualidade de vida e não apresentaram depressão e ansiedade

Spinocerebellar ataxia type 2 (SCA2) is one of autosomal dominant cerebellar ataxias frequently, resulting in significant progressive functional impairment in the lives of carriers. Studies related the SCA2 in Brazil are scarce. The objective of this study was to describe clinical features of five members of same family with SCA2 and correlate them with the quality of life, depression and anxiety. Clinical aspects evaluated included age at onset, duration of disease and application of the International Cooperative Ataxia Rating Scale (ICARS), besides evaluation of neuroimaging and types of treatment. For assessment of anxiety and depression was used Beck Scale and for the quality of life was used SF-36. Regarding the genetic study was evaluated the number of repetitions of trinucleotide CAG. Analysis descriptive and inferential statistics was held. Early ages ranged from 14 to 30 years and duration of disease 8 to 27. The further expansion of trinucleotide CAG was 48 related to the lower age of onset and worse ataxia. Clinical characterization obtained by ICARS was variable and all showed a decrease in quality of life especially in the areas: limitations due to physical aspects, emotional aspects and functional capacity. The scores obtained by the Beck Scale for depression and anxiety were low in all individuals. There was correlation, but no statistical significance between disease duration and functional capacity and between disease duration and ICARS. Individuals with SCA2 analysed in this study had clinical variation, impairment of motor skills and quality of life and did not present depression and anxiety

Spinocerebellar ataxias: genotype-phenotype correlations in 104 Brazilian families

OBJECTIVE: Spinocerebellar ataxias are neurodegenerative disorders involving the cerebellum and its connections. There are more than 30 distinct subtypes, 16 of which are associated with an identified gene. The aim of the current study was to evaluate a large group of patients from 104 Brazilian families with spinocerebellar ataxias. METHODS: We studied 150 patients from 104 families with spinocerebellar ataxias who had received molecular genetic testing for spinocerebellar ataxia types 1, 2, 3, 6, 7, 8, 10, 12, 17, and dentatorubral-pallidoluysian atrophy. A statistical analysis of the results was performed using basic descriptive statistics and the correlation coefficient (r), Student's t-test, chi-square test, and Yates' correction. The statistical significance level was established for p-values <0.05. RESULTS: The results show that the most common subtype was spinocerebellar ataxia 3, which was followed by spinocerebellar ataxia 10. Moreover, the comparison between patients with spinocerebellar ataxia 3, spinocerebellar ataxia 10, and other types of spinocerebellar ataxia revealed distinct clinical features for each type. In patients with spinocerebellar ataxia 3, the phenotype was highly pleomorphic, although the most common signs of disease included cerebellar ataxia (CA), ophthalmoplegia, diplopia, eyelid retraction, facial fasciculation, pyramidal signs, and peripheral neuropathy. In patients with spinocerebellar ataxia 10, the phenotype was also rather distinct and consisted of pure cerebellar ataxia and abnormal saccadic eye movement as well as ocular dysmetria. Patients with spinocerebellar ataxias 2 and 7 presented highly suggestive features of cerebellar ataxia, including slow saccadic ocular movements and areflexia in spinocerebellar ataxia 2 and visual loss in spinocerebellar ataxia 7. CONCLUSIONS: Spinocerebellar ataxia 3 was the most common subtype examined, followed by spinocerebellar ataxia 10. Patients with spinocerebellar ataxia 2 and 7 demonstrated highly suggestive features, whereas the phenotype of spinocerebellar ataxia 3 patients was highly pleomorphic and spinocerebellar ataxia 10 patients exhibited pure cerebellar ataxia. Epilepsy was absent in all of the patients with spinocerebellar ataxia 10 in this series.

Clinical and genetic analysis of 29 Brazilian patients with Huntington's disease-like phenotype / Análise clínica e genética em 29 pacientes Brasileiros com fenótipo doença de Huntington-símile

Huntington's disease (HD) is a neurodegenerative disorder characterized by chorea, behavioral disturbances and dementia, caused by a pathological expansion of the CAG trinucleotide in the HTT gene. Several patients have been recognized with the typical HD phenotype without the expected mutation. The objective of this study was to assess the occurrence of diseases such as Huntington's disease-like 2 (HDL2), spinocerebellar ataxia (SCA) 1, SCA2, SCA3, SCA7, dentatorubral-pallidoluysian atrophy (DRPLA) and chorea-acanthocytosis (ChAc) among 29 Brazilian patients with a HD-like phenotype. In the group analyzed, we found 3 patients with HDL2 and 2 patients with ChAc. The diagnosis was not reached in 79.3 percent of the patients. HDL2 was the main cause of the HD-like phenotype in the group analyzed, and is attributable to the African ancestry of this population. However, the etiology of the disease remains undetermined in the majority of the HD negative patients with HD-like phenotype.

A doença de Huntington (DH) é uma doença neurodegenerativa caracterizada por coréia, alterações comportamentais e demência, causada por uma expansão patológica do trinucleotídeo CAG no gene HTT. Vários pacientes têm sido descritos com o fenótipo típico para a DH porém sem a mutação esperada. O objetivo deste estudo foi avaliar a ocorrência de doenças como doença de Huntington-símile 2 (DHS-2), ataxias espinocerebelares tipo 1, 2, 3 e 17, atrofia dentatorubral-palidoluisiana e coreo-acantocitose (CAc) entre 29 pacientes brasileiros com fenótipo doença de Huntington-símile. No grupo analisado, encontramos 3 pacientes com DHS-2 e 2 pacientes com CAc. O diagnóstico permaneceu obscuro em 79,3 por cento dos pacientes. DHS-2 foi a principal causa do fenótipo DH-símile no grupo analisado, provavelmente devido a ancestralidade africana na população brasileira. Entretanto, a etiologia permaneceu indeterminada na maioria dos pacientes avaliados.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS): typical clinical and neuroimaging features in a Brazilian family / Ataxia espástica autossômica recessiva de Charlevoix-Saguenay (ARSACS): aspectos clínicos e de neuroimagem típicos em uma família brasileira

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a neurodegenerative disorder characterized by late-infantile onset spastic ataxia and other neurological features. ARSACS has a high prevalence in northeastern Quebec, Canada. Several ARSACS cases have been reported outside Canada in recent decades. This is the first report of typical clinical and neuroimaging features in a Brazilian family with probable diagnosis of ARSACS.

A ataxia espástica autossômica recessiva de Charlevoix-Saguenay (ARSACS) é doença degenerativa do sistema nervoso, caracterizada por ataxia associada a espasticidade, entre outras manifestações neurológicas, de início na infância. A doença tem alta prevalência na região de Quebec, no Canadá. Muitos relatos de ARSACS têm sido descritos fora do Canadá nas últimas décadas. Nesse artigo, relatamos a primeira descrição dos aspectos clínicos e de neuroimagem típicos em uma família brasileira com provável diagnóstico de ARSACS.

Spinocerebellar ataxias: microsatellite and allele frequency in unaffected and affected individuals / Ataxias espinocerebelares: freqüência de alelos e microsatélites em indivíduos normais e afetados

The diagnosis and incidence of spinocerebelar ataxias (SCA) is sometimes difficult to analyze due the overlap of phenotypes subtypes and are disorders of mutations caused by CAG trinucleotide repeat expansion. To investigate the incidence of the SCA in Southern Brazil, we analyzed the trinucleotide repeats (CAG)n at the SCA1, SCA2, SCA3, SCA6 and SCA7 loci to identify allele size ranges and frequencies. We examined blood sample from 154 asymptomatic blood donors and 115 individuals with progressive ataxias. PCR products were submitted to capillary electrophoresis. In the blood donors, the ranges of the five loci were: SCA1, 19 to 36 (CAG)n; SCA2, 6 to 28 (CAG)n; SCA3, 12 to 34 (CAG)n; SCA6, 2 to 13 (CAG)n; and SCA7, 2 to 10 (CAG)n. No deviations from Hardy-Weinberg equilibrium were detected. In the ataxia group, we found (CAG)n above the range of the asymptomatic blood donors in SCA3 (21.74 percent) followed by SCA2 (5.22 percent), SCA7 (2.61 percent), SCA6 (0.87 percent), and no cases of SCA1. The remaining 80 cases (69.56 percent) have different diagnoses from the type here studied. These data defined the alleles and their frequencies, as well as demonstrated their stability in the population not affected. The molecular diagnosis test confirmed the clinical diagnosis in 28/45 cases and classified another 7/70 from the clinical unclassified ataxias group.

A incidência e o diagnóstico das ataxias espinocerebelares (SCA) é algumas vezes difícil de avaliar devido a sobreposição dos diversos subtipos e por algumas serem devido a mutações das expansões do mesmo trinucleotídeo CAG. Para investigar a incidências das SCA no sul do Brasil, analisamos as repetições do trinucleotídeo (CAG)n nos loci das SCA1, SCA2, SCA3, SCA6 e SCA7, a fim de identificar os seus limites e freqüência. Examinamos o sangue de 154 doadores de sangue assintomáticos e 115 pacientes com ataxias progressivas. O produto do PCR do sangue foi submetido a eletroforese capilar. Nos doadores de sangue, as expansões encontradas nos cinco loci foram: SCA1, 19 a 36 (CAG)n; SCA2, 6 a 28 (CAG)n; SCA3, 12 a 34 (CAG)n; SCA6, 2 a 13 (CAG)n; and SCA7, 2 a 10 (CAG)n. Não foi detectado desequilíbrio na equação de Hardy-Weinberg. No grupo das ataxias encontramos repetições CAG acima das freqüências dos doadores de sangue na SCA3 (21,7 por cento), seguido da SCA2 (5,22 por cento), SCA7 (2,61 por cento), SCA6 (0,8 por cento) e não foi encontrado nenhum caso de SCA1. Os 80 casos restantes (69,56 por cento) devem ter uma forma de ataxia diferente das aqui estudadas. Esses dados definem os alelos e suas freqüências, bem como demonstram a sua estabilidade na população não afetada. O diagnóstico molecular confirmou o diagnóstico clínico em 28/45 dos casos e permitiu classificar outros 7/70 que pertenciam ao grupo de ataxias clinicamente não classificadas.

Joubert syndrome: a major brain malformation.

Joubert syndrome is a rare genetic disorder characterised by dysplasia of the cerebellar vermis and a malformed brainstem causing ataxia, tachypnoea, nystagmus, hypotonia and mental retardation. An early case of a two-month-old infant presenting with the symptoms mentioned above with the diagnosis of Joubert syndrome is presented here. MRI revealed characteristic "molar tooth" appearance of superior cerebellar peduncles. This case is unusual as it was diagnosed in early infancy.

Efeitos da intervenção fisioterapêutica nas habilidades funcionais e no equilíbrio de uma paciente com ataxia espinocerebelar: estudo de caso / Effects of a physical therapy intervention on balance and functional abilities of a patient with spinocerebellar ataxia: case report

As ataxias espinocerebelares (AEC) formam um grupo heterogênio de doenças degenerativas do sistema nervoso central, com disfunção cerebelar manifestada por ataxia da marcha...

Spinocerebellar ataxias (SCA) form a heterogeneous group of degenerativ diseases of the central system, where cerebellar disease of the central nervous system, where cerebellar disorders reflect in gait ataxia, incoordination, followed by pyramidal signs...

Spinocerebellar ataxia--type 6.

Fifty six years lady presented with pure cerebellar ataxia with positive family history from paternal side presented to our clinic. DNA screening found to be SCA6. This is the first case report of SCA6 from India.

Spinocerebellar ataxia type 2 in seven Korean families: CAG trinucleotide expansion and clinical characteristics

Studies on spinocerebellar ataxias (SCA) have been hampered by a lack of disease markers. Clinical and pathological heterogeneity also made the classification unreliable. Linkage studies established that there are multiple subtypes of SCA. Five types are found to have unstable CAG expansion; the diagnosis can be established by molecular genetic study. Therefore, we systemically screened degenerative ataxia patients for these five SCA types, and identified eight patients with SCA2 (seven from six families and one sporadic case). This paper presents the clinical information on the seven patients, whose clinical information was available in detail. CAG repeat expansion in the patients ranged from 38 to 47 (normal control, 19 to 27). The onset ages ranged from 16 to 41 with 27.1 years as the mean, which correlated inversely with repeat lengths. All patients presented dysarthria and gait ataxia. Upper limb dysmetria or dysdiadochokinesia appeared later but progressed, causing severe disability. Slow saccade (4 patients in 7) and decreased DTR (4 in 7) were common. MRIs showed severe atrophy of the brainstem and cerebellum in all patients. We conclude that SCA2 is the most frequent type in Korea and carries rather pure cerebellar syndrome, slow saccade, and hyporeflexia.