Twenty-five years since the identification of the first SCA gene: history, clinical features and perspectives for SCA1.

Spinocerebellar ataxias (SCA) are a clinically and genetically heterogeneous group of monogenic diseases that share ataxia and autosomal dominant inheritance as the core features. An important proportion of SCAs are caused by CAG trinucleotide repeat expansions in the coding region of different genes. In addition to genetic heterogeneity, clinical features transcend motor symptoms, including cognitive, electrophysiological and imaging aspects. Despite all the progress in the past 25 years, the mechanisms that determine how neuronal death is mediated by these unstable expansions are still unclear. The aim of this article is to review, from an historical point of view, the first CAG-related ataxia to be genetically described: SCA 1.

Twenty-five years since the identification of the first SCA gene: history, clinical features and perspectives for SCA1 / Vinte e cinco anos desde a identificação do primeiro gene das SCAs: história, aspectos clínicos e perspectivas para a SCA1

ABSTRACT Spinocerebellar ataxias (SCA) are a clinically and genetically heterogeneous group of monogenic diseases that share ataxia and autosomal dominant inheritance as the core features. An important proportion of SCAs are caused by CAG trinucleotide repeat expansions in the coding region of different genes. In addition to genetic heterogeneity, clinical features transcend motor symptoms, including cognitive, electrophysiological and imaging aspects. Despite all the progress in the past 25 years, the mechanisms that determine how neuronal death is mediated by these unstable expansions are still unclear. The aim of this article is to review, from an historical point of view, the first CAG-related ataxia to be genetically described: SCA 1.

RESUMO As ataxias espinocerebelares (SCA) são um grupo clínico e geneticamente heterogêneo de doenças monogênicas que compartilham ataxia e herança autossômica dominante como características principais. Uma proporção importante de SCAs é causada por expansões de repetição de trinucleotídeos CAG na região de codificação de diferentes genes. Além da heterogeneidade genética, os aspectos clínicos transcendem os sintomas motores, incluindo aspectos cognitivos, eletrofisiológicos e de imagem. Apesar de todo o progresso feito nos últimos 25 anos, os mecanismos que determinam como se dá a morte neuronal mediada por essas expansões instáveis ainda não estão claros. O objetivo deste artigo é revisar, de um ponto de vista histórico, a primeira ataxia geneticamente relacionada com o CAG descrita: SCA 1.

Spinocerebellar ataxias.

There are over 40 autosomal dominant spinocerebellar ataxias (SCAs) now identified. In this chapter we delineate the phenotypes of SCAs 1-44 and dentatorubral-pallidoluysian atrophy (DRPLA) and highlight the clinical and genetic features of the well characterised SCAs in detail in the main section of the chapter, along with their frequency and age at onset. We have included a section on the key phenotypic features of rare spinocerebellar ataxias and discuss rare and unusual presentations and genetic mechanisms of the ataxias and show differences between adult and paediatric presentations. We look at unusual mechanisms where knowledge is evolving in some dominant ataxias. For ease of reference we have tabulated historical aspects of the ataxias, major neurological diagnostic features, ataxias with predominant paediatric and infantile onset and list recognisable nerve conduction features. We comment on the anti-sense ataxia gene mechanisms and we discuss potential developments including exome sequencing and potential therapeutic options. A gene table listing all of the identified SCAs and DRPLA is also included with key references and gene locations and symbols with OMIM reference numbers for further reading.

Professor Wadia's contributions to neurology and spinocerebellar ataxia type 2.

The authors present a historical review of the seminal contributions of Professor N. H. Wadia (1925-2016) to neurology, in particular, the first description of spinocerebellar ataxia type 2.

Professor Wadia's contributions to neurology and spinocerebellar ataxia type 2 / A contribuição do professor Wadia à neurologia e a ataxia espinocerebelar tipo 2

ABSTRACT The authors present a historical review of the seminal contributions of Professor N. H. Wadia (1925-2016) to neurology, in particular, the first description of spinocerebellar ataxia type 2.

RESUMO Os autores apresentam uma revisão histórica sobre a contribuição seminal do Professor N.H. Wadia para a Neurologia, em particular, a primeira descrição mundial da ataxia espinocerebelar tipo 2.

Spinocerebellar ataxia type 15.

Spinocerebellar ataxia type 15 (SCA15), first described in 2001, is a slowly progressive, relatively pure dominantly inherited ataxia. Six pedigrees have been reported to date, in Anglo-Celtic and Japanese populations. Other than notably slow progression, its main distinguishing characteristic is tremor, often affecting the head, which is seen in about half of affecteds and which may be the presenting feature. Neuroradiology shows cerebellar atrophy, particularly affecting the anterior and dorsal vermis. SCA15 is due to various deletions of the inositol 1,4,5-triphosphate receptor 1 gene (ITPR1) on the distal short arm of chromosome 3. The potential of point mutations in ITPR1 to cause SCA15 is not yet confirmed. "SCA16" has now been shown to be due to an ITPR1 mutation, and has now been subsumed into SCA15.

Abraham Lincoln did not have type 5 spinocerebellar ataxia.

An autosomal dominant genetic disorder, type 5 spinocerebellar ataxia (SCA5), occurs in multiple descendants of one paternal uncle and one paternal aunt of President Abraham Lincoln. It has been suggested that Lincoln himself had the disease and that his DNA should be tested for an SCA5-conferring gene. Herein, I review the pertinent phenotypes of Lincoln, his father, and his paternal grandmother, and conclude that 1) Lincoln's father did not have SCA5, and, therefore, that Lincoln was not at special risk of the disease; 2) Lincoln had neither subclinical nor visible manifestations of SCA5; 3) little evidence suggests SCA5 is a "Lincolnian" disorder; and 4) without additional evidence, Lincoln's DNA should not be tested for SCA5.

The history of spinocerebellar ataxia type 10 in Brazil: travels of a gene.

The authors report the history of spinocerebellar ataxia 10 (SCA10), since its first report in a large Portuguese-ancestry family with autosomal dominant pure cerebellar ataxia, till the final identification of further families without Mexican ancestry. These families present a quite different phenotype from those SCA10 families described in Mexico.

The history of spinocerebellar ataxia type 10 in Brazil: travels of a gene

The authors report the history of spinocerebellar ataxia 10 (SCA10), since its first report in a large Portuguese-ancestry Family with autosomal dominant pure cerebellar ataxia, till the final identification of further families without Mexican ancestry. These families present a quite different phenotype from those SCA10 families described in Mexico.

Os autores apresentam a história da descoberta da ataxia espinocerebelar tipo 10 (AEC10) no Brasil, desde o primeiro relato em uma família com ancestrais portugueses com ataxia cerebelar pura, autossômica dominante, até a identificação de famílias sem ancestrais mexicanos. Essas famílias apresentam um fenótipo de AEC10, com ataxia cerebelar "pura", distinta daquele descrito nas famílias no México.

[Hereditary ataxias in Cuba. Historical, epidemiological, clinical, electrophysiological and quantitative neurological features]. / Las ataxias hereditarias en Cuba. Aspectos históricos, epidemiológicos, clínicos, electrofisiológicos y de neurología cuantitativa.

OBJECTIVE: This review has been designed to describe the main clinical, epidemiological, electrophysiological, molecular and quantitative neurological characteristics in SCA2. DEVELOPMENT: The prevalence rate of patients with ataxia in Holguin province is 43 per 100,000 inhabitants. The prevalence of family members at risk of having this disorder is 159.33 per 100 thousand in this province. The main neurophysiological abnormality observed was reduction in the amplitudes of sensory potentials. These alterations are the expression of a predominantly axonal peripheral lesion with signs of myelin damage. Techniques of quantitative neurology were developed for evaluation of the main disorders of coordination such as asymmetry and adiadochokinesis. In Cuba 125 families have hereditary ataxia, 772 patients and 8 to 10,000 family members are at risk of developing this condition. Seventy percent of the patients with ataxia are concentrated in Holguin province. The most severely affected towns are Báguanos (a rate of 129.20 per 100,000 inhabitants), Holguin (71.85 per 100,000) and Cacocúm (69.83 per 100,000). These are the highest rates in the world. CONCLUSIONS: The commonest molecular form in Cuba is the SCA2, observed in 120 families. Clinically it is characterized by a cerebellar syndrome associated with disorders of eye movements and osteotendinous reflexes.