Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004134 (ataxia)
 15,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies of inherited neurodegenerative disorders have suggested a linkage between the propensity toward aggregation of mutant protein and disease onset. This is particularly apparent for polyglutamine (polyQ) diseases caused by expansion of CAG-trinucleotide repeats. However, a quantitative framework for relating aggregation kinetics with molecular mechanisms of neurodegeneration initiation is lacking. Here, using the repeat-length-dependent age-of-onset in polyQ diseases, we derived a mathematical model based on nucleation of aggregation kinetics to describe genotype-phenotype correlations, and validated the model using both in vitro data and clinical data. Instead of describing polyQ aggregation kinetics with a derivative equation, our model divided age-of-onset (equivalent to the time required for aggregation) into two processes: nucleation lag time (a first-order exponential function of CAG-repeat length) and elongation time. With the exception of spinocerebellar ataxia (SCA) 3, the relation between CAG-repeat length and age-of-onset in all examined polyQ diseases, including Huntington's disease, dentatorubral-pallidoluysian atrophy and SCA1, -2, -6 and -7, could be well explained by three parameters derived from linear regression analysis based on the nucleated growth polymerization model. These parameters composed of probability of nucleation at an individual repeat, a protein concentration associated factor, and elongation time predict the overall features of neurodegeneration initiation, including constant risk for cell death, toxic polyQ species, main pathological subcellular site and the contribution of cellular factors. Our model also presents an alternative therapeutic strategy according to the distinct subcellular loci by the finding that nuclear localization of soluble mutant protein monomers itself has great impact on disease onset.
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PMID:Nucleation of protein aggregation kinetics as a basis for genotype-phenotype correlations in polyglutamine diseases. 1960 94

We presented a 28-year-old female with dentatorubral-pallidoluysian atrophy (DRPLA) who had been followed from the pre-clinical stage. Her mother and elder brother were diagnosed as DRPLA at autopsy. Though the genetic diagnosis was not performed, we diagnosed this patient as DRPLA from her clinical course and family history. She first visited our hospital at age 14 with a symptoms of mental retardation. Generalized tonic-clonic type epilepsy developed at age 15, and valproate was prescribed from age 24. Gait disturbance and mental deterioration gradually progressed from age 15. We had performed gait analyses and brain MRI studies at regular intervals from age 14 to 27. She could walk even with gait disturbance until her early 20s. At one year after marked ataxia was recorded on gait analysis, she rapidly regressed and became unable to walk. Following this patient over a long period of time presented an opportunity to gather informative data regarding the progression of this disorder.
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PMID:[Female with dentatorubral-pallidoluysian atrophy followed for 14 years from the pre-clinical stage: availability of gait analysis]. 1961 87

The spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative diseases. Researchers have recently found that SCA type 11 (SCA11) is associated with mutations in the TTBK2 gene. In our previous work, we performed mutation detection in SCA1, 2, 3, 6, 7, 8, 10, 12, 17 and dentatorubral-pallidoluysian atrophy gene in Chinese SCA patients, but the genes responsible for approximately 40% of our patients have not yet been identified. To investigate the frequency of SCA11 in Chinese SCA patients, we examined the TTBK2 gene in 68 unrelated probands diagnosed with dominantly inherited ataxia using the denaturing high-performance liquid chromatography method. All analyzed samples displayed the normal elution profile, which denoted that no disease-related mutation was identified. We provided the evidence that SCA11 is a rare form of ataxia in China.
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PMID:Spinocerebellar ataxia type 11 in the Chinese Han population. 1976 75

Neuronal intranuclear inclusions (NIIs) are the pathological hallmark of polyglutamine (polyQ) diseases. We previously found that the RNA-binding protein FUS/TLS is the major component of nuclear polyQ aggregates of a cellular model of Huntington disease. In this study, we revealed that FUS/TLS binds to NIIs in the human brains from patients with spinocerebellar ataxia type 1, 2, 3, and dentatorubral-pallidoluysian atrophy. Recent reports have revealed that mutations in FUS/TLS gene are responsible for familial amyotrophic lateral sclerosis 6 (ALS6). Our results indicated that changing FUS/TLS to an insoluble form may be a common process in polyQ diseases and ALS6.
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PMID:The RNA-binding protein FUS/TLS is a common aggregate-interacting protein in polyglutamine diseases. 1983 57

Spinocerebellar ataxia type15 (SCA15) is a pure ataxia characterized by very slow progression. Only seven families have been identified worldwide, in which partial deletions and a missense mutation of the inositol triphosphate receptor type I gene (ITPR1) have been reported. We examined a four-generation Italian family segregating an autosomal dominant cerebellar ataxia, in which linkage analysis was positive for the SCA15 locus. We performed a genomic real-time polymerase chain reaction to search for ITPR1 gene deletions in this family and in 60 SCA index cases negative for mutations in the SCA1-3, 6-8, 10, 12,and dentatorubral-pallidoluysian atrophy genes. The deleted segments were characterized using a custom array comparative genomic hybridization analysis. We have identified two families with an ITPR1 gene deletion: in one, the deletion involved ITPR1 only, while in the other both sulfatase-modifying factor 1 and ITPR1. Clinical data of ten patients and brain MRI (available for six) showed that the phenotype substantially overlapped known SCA15 cases,but we also noted buccolingual dyskinesias, facial myokymias,and pyramidal signs never reported in SCA15. ITPR1 expression analysis of two deleted cases showed a half dose. Our results further support ITPR1 gene as causative of SCA15. The families reported show that SCA15 is present in Italy and has a greater variability in the age at onset and clinical features than previously reported. We propose that the search for ITPR1 deletions is mandatory in the clinical hypothesis of SCA15 and that ITPR1-reduced expression in blood may be a useful marker to identify SCA15 patients harboring genomic deletions and possibly point mutations causing reduction of mRNA level.
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PMID:Two Italian families with ITPR1 gene deletion presenting a broader phenotype of SCA15. 2008 66

We report a 50-year-old woman with an unremarkable birth and developmental history, and with no family history of neurological disorders. The patient had a 6-year history of progressive cervical dystonia, oral dyskinesia, and hyperreflexia. She was initially considered to have spastic paraparesis of unknown cause. Because brain MRI showed mild atrophy of the cerebellar vermis, genetic analysis for spinocerebellar ataxia types 1, 2, 3, 6, 7, 8, 12, and 17, and dentatorubral-pallidoluysian atrophy was performed. The results revealed an abnormal expansion of CAG repeats (38 repeats) in one allele of ATXN2, and the patient was diagnosed with spinocerebellar ataxia type 2 (SCA2). She had no major clinical features of SCA2 such as cerebellar ataxia, slow saccade, or hyporeflexia. Recent reports have shown the CAG repeat expansion in ATXN2 to be detected in patients with familial L-dopa-responsive parkinsonism. The present case suggests that CAG repeat expansion in ATXN2 may be detected in some patients with spastic paraparesis, and that wide variations of clinical manifestations exist in SCA2.
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PMID:[A case of spinocerebellar ataxia type 2 presenting with a clinical course similar to spastic paraparesis]. 2096 Sep 29

We screened a cohort of 181 patients with features of primary progressive ataxia and chorea for spinocerebellar ataxias 17 (SCA17) mutation after excluding other known SCAs, Huntington's disease (HD), dentatorubral-pallidoluysian atrophy (DRPLA), and non-genetic causes. This study included patients with known family history of SCA, those with sporadic onset and cases of uncertain family history. Two unrelated patients with Huntington's disease-like phenotype and cerebellar signs are described with homozygous expansions of 47 and 48 CAG/CAA repeats. A family member with early signs of ataxia was found to carry 37 and 48 repeats. There were fewer CAA interruptions in the repeat sequences of patients than in the controls. The normal repeat range in controls was 21-42, with 91% of the alleles located between 33 and 39 repeats. This is the first report of rare homozygous SCA17 mutation in Indian patients presenting with HD-like phenotype.
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PMID:Spinocerebellar ataxia type 17 in Indian patients: two rare cases of homozygous expansions. 2110 34

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% 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.
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PMID:Clinical and genetic analysis of 29 Brazilian patients with Huntington's disease-like phenotype. 2175 13

To date there are 9 known diseases caused by an expanded polyglutamine repeat, with the most prevalent being Huntington's disease. Huntington's disease is a progressive autosomal dominant neurodegenerative disorder for which currently no therapy is available. It is caused by a CAG repeat expansion in the HTT gene, which results in an expansion of a glutamine stretch at the N-terminal end of the huntingtin protein. This polyglutamine expansion plays a central role in the disease and results in the accumulation of cytoplasmic and nuclear aggregates. Here, we make use of modified 2'-O-methyl phosphorothioate (CUG)n triplet-repeat antisense oligonucleotides to effectively reduce mutant huntingtin transcript and protein levels in patient-derived Huntington's disease fibroblasts and lymphoblasts. The most effective antisense oligonucleotide, (CUG)(7), also reduced mutant ataxin-1 and ataxin-3 mRNA levels in spinocerebellar ataxia 1 and 3, respectively, and atrophin-1 in dentatorubral-pallidoluysian atrophy patient derived fibroblasts. This antisense oligonucleotide is not only a promising therapeutic tool to reduce mutant huntingtin levels in Huntington's disease but our results in spinocerebellar ataxia and dentatorubral-pallidoluysian atrophy cells suggest that this could also be applicable to other polyglutamine expansion disorders as well.
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PMID:Targeting several CAG expansion diseases by a single antisense oligonucleotide. 2190 28

Dentatorubral-pallidoluysian atrophy (DRPLA) is an autosomal dominant progressive neurodegenerative disorder with intellectual deterioration and various motor deficits including ataxia, choreoathetosis, and myoclonus, caused by an abnormal expansion of CAG repeats in the DRPLA gene. Longer expanded CAG repeats contribute to an earlier age of onset, faster progression, and more severe neurological symptoms in DRPLA patients. In this study, we have established DRPLA transgenic mouse lines (sublines) harboring a single copy of the full-length mutant human DRPLA gene carrying various lengths of expanded CAG repeats (Q76, Q96, Q113, and Q129), which have clearly shown motor deficits and memory disturbance whose severity increases with the length of expanded CAG repeats and age, and successfully replicated the CAG repeat length- and age-dependent features of DRPLA patients. Neuronal intranuclear accumulation of the mutant DRPLA protein has been suggested to cause transcriptional dysregulation, leading to alteration in gene expression and neuronal dysfunction. In this study, we have conducted a comprehensive analysis of gene expression profiles in the cerebrum and cerebellum of transgenic mouse lines at 4, 8, and 12 weeks using multiple microarray platforms, and demonstrated that both the number and expression levels of the altered genes are highly dependent on CAG repeat length and age in both brain regions. Specific groups of genes and their function categories were identified by further agglomerative cluster analysis and gene functional annotation analysis. Calcium signaling and neuropeptide signaling, among others, were implicated in the pathophysiology of DRPLA. Our study provides unprecedented CAG-repeat-length-dependent mouse models of DRPLA, which are highly valuable not only for elucidating the CAG-repeat-length-dependent pathophysiology of DRPLA but also for developing therapeutic strategies for DRPLA.
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PMID:DRPLA transgenic mouse substrains carrying single copy of full-length mutant human DRPLA gene with variable sizes of expanded CAG repeats exhibit CAG repeat length- and age-dependent changes in behavioral abnormalities and gene expression profiles. 2234 74


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