Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0040822 (tremor)
 18,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Spinocerebellar ataxia 2 (SCA2) is one of the loci for the clinically and genetically heterogeneous group of autosomal dominant type I cerebellar ataxias. After initial linkage to chromosome 12q in Cuban families, SCA2 was shown to be the gene responsible for the disease in Italian, Tunisian, French-Canadian, Austrian-Canadian and Martinican kindreds with dominant ataxia, and the candidate interval was reduced to 6.4 cM between markers D12S84 and D12S79. Comparison of patients from families of different geographical origins clearly demonstrates the clinical interfamilial variability of the clinical signs which reaches statistical significance for the frequency of extrapyramidal rigidity, postural tremor and dementia. The most striking difference between the 29 Martinican SCA2 patients and those with SCA1 on chromosome 6p or SCA3/MJD on chromosome 14q is the greater frequency of hyporeflexia in the former. A mean 12.5 year anticipation is observed, with a more rapid clinical course of the disease in successive generations, indicating that an expanded trinucleotide repeat probably constitutes the underlying molecular mechanism.
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PMID:Autosomal dominant cerebellar ataxia type I linked to chromosome 12q (SCA2: spinocerebellar ataxia type 2). 761 88

We studied the clinical features and molecular genetics of a family, afflicted with a form of atypical parkinsonism, originating from the Madeira Islands of Portugal. We examined four affected individuals and reviewed clinical information on one other affected family member. Mean age at onset was 31 years. Parkinsonism (akinesia, rigidity, gait disturbance) was the most prominent feature in advanced disease. Levodopa responsiveness with peak-dose dyskinesia was present in one individual. Initial symptoms and other clinical features were variable and included other extrapyramidal signs (dystonia, action tremor of the limbs and bulbar muscles, synkinesis), ophthalmologic abnormalities (ptosis, slow saccades, progressive external ophthalmoplegia, hypometric saccades, saccadic pursuit movements), speech abnormalities (dysarthria, hypernasality), cortical impairment (dementia, frontal lobe dysfunction, palilalia, perseveration), minor cerebellar signs (dysmetria, gait ataxia), pyramidal abnormalities (spasticity, hyperreflexia), and peripheral nervous system abnormalities (propioceptive loss, areflexia, distal weakness, atrophy). The length of trinucleotide repeats in the MJD1 gene was in the normal range for all affected individuals.
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PMID:Atypical parkinsonism in a family of Portuguese ancestry: absence of CAG repeat expansion in the MJD1 gene. 915 59

Seventy-seven families with autosomal dominant cerebellar ataxia were analyzed for the CAG repeat expansions causing spinocerebellar ataxia (SCA) types 1, 2, 3, and 6. The SCA1 mutation accounted for 9%, SCA2 for 10%, SCA3 for 42%, and SCA6 for 22% of German ataxia families. Seven of 27 SCA6 patients had no family history of ataxia. Age at onset correlated inversely with repeat length in all subtypes. Yet the average effect of one CAG unit on onset age was different for each SCA subtype. We compared clinical, electrophysiological, and magnetic resonance imaging (MRI) findings to identify phenotypic characteristics of genetically defined SCA subtypes. Slow saccades, hyporeflexia, myoclonus, and action tremor proposed SCA2. SCA3 patients frequently developed diplopia, severe spasticity or pronounced peripheral neuropathy, and impaired temperature discrimination, apart from ataxia. SCA6 presented with a predominantly cerebellar syndrome and patients often had onset after 55 years of age. SCA1 was characterized by markedly prolonged peripheral and central motor conduction times in motor evoked potentials. MRI scans showed pontine and cerebellar atrophy in SCA1 and SCA2. In SCA3, enlargement of the fourth ventricle was the main sequel of atrophy. SCA6 presented with pure cerebellar atrophy on MRI. However, overlap between the four SCA subtypes was broad.
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PMID:Autosomal dominant cerebellar ataxia: phenotypic differences in genetically defined subtypes? 940 86

Movement disorders are well known features of some dominant hereditary ataxias (HA), specially SCA3/Machado-Joseph disease and dentatorubropallidolusyan atrophy. However, little is known about the existence and classification of movement disorders in other dominant and recessive ataxias. We prospectively studied the presence of movement disorders in patients referred for HA over the last 3 years. Only those patients with a confirmed family history of ataxia were included. We studied 84 cases of HA, including 46 cases of recessive and 38 cases of dominant HA. Thirty out of 46 cases of recessive HA could be classified as: Friedreich ataxia (FA), 29 cases; vitamin E deficiency, 1 case. Twenty-three out of 38 cases of dominant HA could be classified as: SCA 2, 4 cases; SCA 3, 8 cases; SCA 6, 4 cases; SCA 7, 6 cases and SCA 8, 1 case. We observed movement disorders in 20/38 (52%) patients with dominant HA and 25/46 (54%) cases with recessive HA, including 16 patients (16/29) with FA. In general, postural tremor was the most frequent observed movement disorder (27 cases), followed by dystonia (22 cases). Five patients had akinetic rigid syndrome, and in 13 cases, several movement disorders coexisted. Movement disorders are frequent findings in HA, not only in dominant HA but also in recessive HA.
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PMID:Movement disorders in hereditary ataxias. 1222 Jun 93

We describe 5 cases with a rare combination of young-onset, slowly progressive cerebellar ataxia and cervical dystonia. Two were sporadic, whereas the other 3 were familial, including 2 from one family. The age of onset of these cases was between 16 and 37 years. The presenting symptom was cervical dystonia and/or dystonic head tremor in 3 patients and hand or lower limb tremor in 2. In 2 cases, cervical dystonia and/or dystonic head tremor developed approximately 6 to 10 years before cerebellar dysfunction, and in three they developed at the same time. Apart from cervical dystonia, there was mild dystonic limb involvement in 2 cases, but generalized dystonia was not seen. Cerebellar ataxia was slowly progressive. A literature search showed 10 cases of cervical dystonia associated with genetically undetermined (n = 5) or genetically proven (n = 5) spinocerebellar ataxia (SCA). When the genotype was known, these patients had either SCA3, 6, 7, or 12. However, our 5 cases (or their first-degree relatives) tested negative for SCA1, 2, 3, 6, and 7, and in the 4 cases (or their first-degree relatives) tested for SCA12, the result was negative. We propose that this rare phenotype manifesting as a combination of cerebellar ataxia and cervical dystonia may represent one or more new, as yet uncharacterized, genotypes of inherited young-onset spinocerebellar ataxia.
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PMID:Slowly progressive cerebellar ataxia and cervical dystonia: clinical presentation of a new form of spinocerebellar ataxia? 1253 16

DNA tests in normal subjects and patients with ataxia and Parkinson's disease (PD) were carried out to assess the frequency of spinocerebellar ataxia (SCA) and to document the distribution of SCA mutations underlying ethnic Chinese in Taiwan. MJD/SCA3 (46%) was the most common autosomal dominant SCA in the Taiwanese cohort, followed by SCA6 (18%) and SCA1 (3%). No expansions of SCA types 2, 10, 12, or dentatorubropallidoluysian atrophy (DRPLA) were detected. The clinical phenotypes of these affected SCA patients were very heterogeneous. All of them showed clinical symptoms of cerebellar ataxia, with or without other associated features. The frequencies of large normal alleles are closely associated with the prevalence of SCA1, SCA2, MJD/SCA3, SCA6, and DRPLA among Taiwanese, Japanese, and Caucasians. Interestingly, abnormal expansions of SCA8 and SCA17 genes were detected in patients with PD. The clinical presentation for these patients is typical of idiopathic PD with the following characteristics: late onset of disease, resting tremor in the limbs, rigidity, bradykinesia, and a good response to levodopa. This study appears to be the first report describing the PD phenotype in association with an expanded allele in the TATA-binding protein gene and suggests that SCA8 may also be a cause of typical PD.
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PMID:Genetic testing in spinocerebellar ataxia in Taiwan: expansions of trinucleotide repeats in SCA8 and SCA17 are associated with typical Parkinson's disease. 1475 71

Spinocerebellar ataxias (SCAs) are a clinically heterogeneous group of disorders. Current molecular classification corresponds to the order of gene description (SCA1-SCA 25). The prevalence of SCAs is estimated to be 1-4/100,000. Patients exhibit usually a slowly progressive cerebellar syndrome with various combinations of oculomotor disorders, dysarthria, dysmetria/kinetic tremor, and/or ataxic gait. They can present also with pigmentary retinopathy, extrapyramidal movement disorders (parkinsonism, dyskinesias, dystonia, chorea), pyramidal signs, cortical symptoms (seizures, cognitive impairment/behavioral symptoms), peripheral neuropathy. SCAs are also genetically heterogeneous and the clinical diagnosis of subtypes of SCAs is complicated by the salient overlap of the phenotypes between genetic subtypes. The following clinical features have some specific values for predicting a gene defect: slowing of saccades in SCA2, ophthalmoplegia in SCA1, SCA2 and SCA3, pigmentary retinopathy in SCA7, spasticity in SCA3, dyskinesias associated with a mutation in the fibroblast growth factor 14 (FGF 14) gene, cognitive impairment/behavioral symptoms in SCA17 and DRPLA, seizures in SCA10, SCA17 and DRPLA, peripheral neuropathy in SCA1, SCA2, SCA3, SCA4, SCA8, SCA18 and SCA25. Neurophysiological findings are compatible with a dying-back axonopathy and/or a neuronopathy. Three patterns of atrophy can be identified on brain MRI: a pure cerebellar atrophy, a pattern of olivopontocerebellar atrophy, and a pattern of global brain atrophy. A remarkable observation is the presence of dentate nuclei calcifications in SCA20, resulting in a low signal on brain MRI sequences. Several identified mutations correspond to expansions of repeated trinucleotides (CAG repeats in SCA1, SCA2, SCA3, SCA6, SCA7, SCA17 and DRPLA, CTG repeats in SCA8). A pentanucleotide repeat expansion (ATTCT) is associated with SCA10. Missense mutations have also been found recently. Anticipation is a main feature of SCAs, due to instability of expanded alleles. Anticipation may be particularly prominent in SCA7. It is estimated that extensive genetic testing leads to the identification of the causative gene in about 60-75 % of cases. Our knowledge of the molecular mechanisms of SCAs is rapidly growing, and the development of relevant animal models of SCAs is bringing hope for effective therapies in human.
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PMID:The wide spectrum of spinocerebellar ataxias (SCAs). 1589 52

Spinocerebellar ataxia type 3 (SCA3) is an autosomal dominantly inherited neurodegenerative disorder caused by the expansion of a CAG repeat in the MJD1 gene resulting in an expanded polyglutamine repeat in the ataxin-3 protein. To study the course of the disease, we generated transgenic mice for SCA3 using full-length ataxin-3 constructs containing 15, 70, or 148 CAG repeats, respectively. Control mice (15 CAGs) were phenotypically normal and had no neuropathological findings. However, mice transgenic for ataxin-3 with expanded polyglutamine repeats were severely affected by a strong neurological phenotype with tremor, behavioral deficits, strongly reduced motor and exploratory activity, a hunchback, and premature death at 3 to 6 months of age. Neuropathological examination by immunohistochemical staining revealed ubiquitin- and ataxin-3-positive intranuclear inclusion bodies in a multitude of neurons. Directing ataxin-3 with 148 CAGs to the nucleus revealed an even more pronounced phenotype with more inclusions and earlier death, whereas mice transgenic with the same construct but attached to a nuclear export signal developed a milder phenotype with less inclusions. These studies indicate that nuclear localization of ataxin-3 is required for the manifestation of symptoms in SCA3 in vivo.
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PMID:Nuclear localization of ataxin-3 is required for the manifestation of symptoms in SCA3: in vivo evidence. 1762 2

Anecdotal reports suggest that patients with spinocerebellar ataxia (SCA 2) patients can present with postural tremor with ataxia. We determined the prevalence of SCA2 and SCA3 mutations in a cohort of ET and atypical Parkinsonism patients. A total of 277 subjects comprising of 177 ET and 100 atypical Parkinsonism were examined. We identified one positive case of SCA3 among those who were diagnosed with ET, yielding a prevalence of 0.5%, but a zero prevalence among our atypical Parkinsonism patients. No study subjects carried an abnormal SCA2 repeat expansion. Our study highlights that SCA3 can present initially with ET symptoms, expanding the spectrum of genetic diseases that can be associated with ET-like phenotype. Routine screening for SCA2 and SCA3 in ET and atypical Parkinsonism patients may not be cost effective. However, in the long-term follow-up of patients who present with an ET phenotype, clinicians should be vigilant for other neurological signs, which may be point to an alternate diagnosis.
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PMID:Genetic analysis of SCA 2 and 3 repeat expansions in essential tremor and atypical Parkinsonism. 1771 57

Characterization of disease models of neurodegenerative disorders requires a systematic and comprehensive phenotyping in a highly standardized manner. Therefore, automated high-resolution behavior test systems such as the homecage based LabMaster system are of particular interest. We demonstrate the power of the automated LabMaster system by discovering previously unrecognized features of a recently characterized atxn3 mutant mouse model. This model provided neurological symptoms including gait ataxia, tremor, weight loss and premature death at the age of 12 months usually detectable just 2 weeks before the mice died. Moreover, using the LabMaster system we were able to detect hypoactivity in presymptomatic mutant mice in the dark as well as light phase. Additionally, we analyzed inflammation, immunological and hematological parameters, which indicated a reduced immune defense in phenotypic mice. Here we demonstrate that a detailed characterization even of organ systems that are usually not affected in SCA3 is important for further studies of pathogenesis and required for the preclinical therapeutic studies.
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PMID:Automated behavioral phenotyping reveals presymptomatic alterations in a SCA3 genetrap mouse model. 2274 17


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