Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016719 (Friedreich's ataxia)
 2,098 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Developments in the field of Huntington's disease have focused on the potential benefits of predictive testing. Markers have been described for autosomal dominant cerebellar ataxia and for certain subtypes of Friedrich's ataxia. Argentophilic neuronal and glial inclusions appear to be the first specific pathologic hallmark of multiple system atrophy. "Pure" hereditary spastic paraplegia is not a multisystem disorder of the central nervous system, but a monomorphic and stereotyped disease. Advances in Tourette's syndrome are limited because the presumed gene eludes identification. A new type of myoclonus, propiospinal myoclonus, has been described. Clinical and electrophysiologic criteria for defining primary orthostatic tremor have been proposed. Understanding of the neurophysiologic substrate of essential tremor and myoclonus is improving. New neurologic disorders presenting clinically with prominent movement disorder continue to be described.
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PMID:Choreas, hereditary and other ataxias, tics, myoclonus, and other movement disorders. 850 6

MRI makes it possible to study the in vivo brain and spinal cord morphology of patients with hereditary ataxia. We performed T1- and T2-weighted studies in eleven patients with Friedreich's disease (FD), five with "late onset" FD and ten with early onset cerebellar ataxia with retained tendon reflexes (EOCA). Cervical cord atrophy was constant in FD and "late onset" FD and often associated with atrophy of the cerebellum and of the brainstem; T2-weighted studies showed posterior column degeneration in the cervical cord. The most frequent finding in EOCA was cerebellar atrophy, pure or associated with cervical cord or brainstem atrophy; the cerebellar atrophy was marked in a few cases and was related to disease duration.
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PMID:Magnetic resonance imaging in "typical" and "late onset" Friedreich's disease and early onset cerebellar ataxia with retained tendon reflexes. 853 18

We report the study of motor evoked potentials by magnetic stimulation in 26 subjects with hereditary or sporadic ataxia. The subjects included 15 cases of late onset cerebellar ataxia (12 classified as olivopontocerebellar atrophy (OPCA), 3 as spinocerebellar atrophy (SCA)) and 11 cases of early onset cerebellar ataxia (4 Friedreich's ataxia (FA) and 7 unclassifiable in Friedreich's ataxia (NFA)). All subjects with FA and SCA had delayed central motor conduction times, more accentuated in corticospinal tracts directed to lumbar motoneurons. A similar but less marked slowing was observed in about half of the subjects with OPCA and NFA. In the last two groups the anomalies are more frequent in hereditary than in sporadic forms.
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PMID:Motor evoked potentials by magnetic stimulation in hereditary and sporadic ataxia. 854 32

Trace elements might be related with the pathogenesis of spinocerebellar degeneration (SCD). Mercury produce cerebellar ataxia. However, it was reported that the content of mercury in the hair of patients with SCD was normal. Therefore, mercury may not be directly related with SCD. It was reported that the content of copper in the hair might be high in patients with Friedreich's disease, or low in patients with late cortical cerebellar atrophy. The normal content of zinc in the hair was reported in patients with SCD. The low content of manganese in the hair was suggested in patients with SCD. Usually Parkinsonism was observed in manganese intoxication in man. Lead may produce cerebellar ataxia. These trace elements might cause SCD. However, the relation is still obscure. The further study should be conducted.
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PMID:[Trace elements in spinocerebellar degeneration]. 858 79

This prospective study was undertaken to characterize better electrophysiologically the newly described clinical entity of "Early onset cerebellar ataxia with retained tendon reflexes (EOCA)" and compare it with Olivopontocerebellar atrophy (OPCA) and Friedreich's ataxia (FA). Concentric needle electromyography and motor (median, common peroneal and posterior tibial) and sensory (median, sural and posterior tibial) nerve conduction studies were carried out in 14 patients of EOCA. The results were compared with those of 10 and 16 patients of FA and OPCA respectively. All patients of EOCA had either motor or sensory conduction abnormalities, motor being slightly more frequent than sensory (87.7% versus 78.6%). The neuropathy was distal and symmetrical, lacked correlation with duration or clinical stage of the disease, even between patients of the same family. Electrophysiological studies helped to detect subclinical motor and sensory neuropathy in most of the patients. No characteristic electrophysiologic abnormalities separated patients of EOCA from those of OPCA or FA, though the overall incidence of abnormalities was higher in the latter two groups. It is concluded that subclinical peripheral neuropathy is often present in patients of EOCA. The impaired proprioceptive sensation noted among these patients may be due to large fiber neuropathy rather than posterior column involvement alone. A subgroup of them, who have severe sensory neuropathy, may be difficult to differentiate clinically from patients of FA. The clinical entity of EOCA is indistinguishable electrophysiologically from FA and OPCA.
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PMID:Early onset cerebellar ataxia with retained tendon reflexes (EOCA): an electromyographic study. 887 21

Friedreich's ataxia is an autosomal recessively inherited neurodegenerative disorder caused by expansions of an unstable GAA trinucleotide repeat in the STM7/X25 gene on chromosome 9q. We studied the (GAA)n polymorphism in 178 healthy controls and 102 patients with idiopathic ataxia. The repeat size ranged from 7 to 29 (GAA)n motifs on normal chromosomes and from 66 to 1360 trinucleotide repetitions in Friedreich's ataxia patients. Meiotic instability of expanded alleles was observed without significant differences in maternal and paternal transmissions. Thirty-six of 102 patients were typed homozygous for expanded (GAA)n alleles. Twenty-seven of these presented with the typical Friedreich's ataxia symptoms and nine patients with an atypical Friedreich's ataxia phenotype. Before molecular genetic diagnosis had been performed seven of these patients had been classified as early onset cerebellar ataxia and two as idiopathic sporadic cerebellar ataxia of late onset. In contrast, in one family with typical Friedreich's ataxia phenotype we did not find an expanded allele; this suggests that there can be either point mutations in the X25 gene on both chromosomes or locus heterogeneity in Friedreich's ataxia. The phenotypic spectrum of Friedreich's ataxia is much broader than considered before. Early onset, areflexia, extensor plantar responses and reduced vibration sense should no longer be considered essential diagnostic criteria of Friedreich's ataxia. In comparison with the non-Friedreich's ataxia group hypertrophic cardiomyopathy seems to be the only symptom specific for Friedreich's ataxia. However, it is not obligatory. The phenotype is significantly influenced by the number of GAA repeats with close genotype-phenotype relationships when the smaller of the two alleles is considered. Repeat length correlated inversely with age at onset, onset of dysarthria and progression rate. In conclusion, molecular genetic analysis appears mandatory for the diagnosis and genetic counselling of Friedreich's ataxia. The molecular genetic test should be applied not only to patients with typical Friedreich's ataxia phenotype but also in all cases of idiopathic autosomal recessive or sporadic ataxia.
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PMID:Friedreich's ataxia. Revision of the phenotype according to molecular genetics. 944 68

The aim of the present study was (i) to compare disease progression and survival in different types of degenerative ataxia, and (ii) to identify variables that may modify the rate of disease progression. We included patients suffering from Friedreich's ataxia (FRDA, n = 83), early onset cerebellar ataxia (EOCA, n = 30), autosomal dominant cerebellar ataxia (ADCA) type I (ADCA-I, n = 273), ADCA-III (n = 13) and multiple system atrophy (MSA, n = 67). Molecular genetic testing allowed us to assign 202 ADCA-I patients to one of the following subgroups: spinocerebellar ataxia type I (SCAI, n = 36), SCA2 (n = 56) and SCA3 (n = 110). To assess disease progression we defined the following disease stages: stage 0 = no gait difficulties; stage 1 = disease onset, as defined by onset of gait difficulties; stage 2 = loss of independent gait; stage 3 = confinement to wheelchair; stage 4 = death. Disease progression was most rapid in MSA, intermediate in FRDA, ADCA-I and ADCA-III and slowest in EOCA. The rate of progression was similar in SCA1, SCA2 and SCA3. The CAG repeat length was a significant risk factor for faster progression in SCA2 and SCA3, but not in SCA1. In FRDA, the time until confinement to wheelchair was shorter in patients with earlier disease onset, suggesting that patients with long GAA repeats and early disease onset have a poor prognosis. Female gender increased the risk of becoming dependent on walking aids or a wheelchair, but it did not influence survival in FRDA, SCA3 and MSA. In SCA2, female gender was associated with shortened survival. In MSA, later age of onset increased the risk of rapid progression and death.
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PMID:The natural history of degenerative ataxia: a retrospective study in 466 patients. 957 87

A family with two members who had early-onset cerebellar ataxia (EOCA) with retained tendon reflexes had, in addition to their motor deficits, a progressive impairment of cognitive and visuospatial abilities. We used positron emission tomography (PET) with 11C-flumazenil to study gamma-aminobutyric type A/benzodiazepine receptor binding (BZR) and 18F-2-fluoro-2-deoxy-D-glucose to analyze longitudinally regional cerebral glucose metabolism. Flumazenil-PET demonstrated loss of BZR binding that has not been shown in Friedreich's ataxia and olivopontocerebellar atrophy. These findings may be useful for differentiation of EOCA from other types of cerebellar ataxia. In comparison to age-matched control subjects, these patients showed a global metabolic decline and predominant hypometabolism in the thalamus and cerebellum. The progressive metabolic derangement may be explainable by a disturbed integrity of cognition-related networks resulting from secondary degeneration of cerebello-thalamo-cortical projections.
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PMID:Early-onset cerebellar ataxia (EOCA) with retained reflexes: reduced cerebellar benzodiazepine-receptor binding, progressive metabolic and cognitive impairment. 968 85

We used single photon emission tomography to study regional cerebral perfusion in patients with different forms of spinocerebellar degeneration: 6 patients with Friedreich's ataxia (FA), 6 with early-onset cerebellar ataxia with retained tendon reflexes (EOCA), 5 with autosomal dominant cerebellar ataxia type 1 (ADCA I) and 11 with idiopathic late-onset cerebellar ataxia (ILOCA). The results were related to clinical and magnetic resonance imaging (MRI) findings. Cerebellar hypoperfusion was constant in ADCA I and frequent in patients with other spinocerebellar degenerations. Brain stem hypoperfusion was constant in ADCA I, frequent in ILOCA patients with pontocerebellar atrophy and absent in FA and EOCA. FA and EOCA often showed a reduction in the parietotemporal cortex blood flow, which was not related to cortical atrophy. ILOCA patients had an asymmetric pattern in the temporal areas with decreased blood flow in the right side only. Caudate hypoperfusion was found in ADCA I patients. Cerebral atrophy did not account for changes in regional blood flow, which probably indicate early involvement of cerebral structures.
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PMID:Cerebral blood flow in spinocerebellar degenerations: a single photon emission tomography study in 28 patients. 975 99

Unstable (CAG)n trinucleotide repeat microsatellites are hypothesized to cause schizophrenia. The (CAG)n microsatellite of dominant spinal cerebellar ataxia type 1 (SCA1) is a candidate schizophrenia gene. Autism results from expansions of (CGG)n and (GAA)n trinucleotide repeat stretches at fragile X syndrome (FRAXA), and the recessive Friedreich's ataxia (FA). Dominant ataxia genes may cause schizophrenia and recessive ataxia genes may cause autism. Syndromes with autism show purine synthesis defects (PSDs) and/or pigmentation defects (PDs). Autism is caused by very lengthy expansions of (CAG)n, (CGG)n and (GAA)n repeats, while schizophrenia results from much smaller (CAG)n and (CGG)n repeat expansions.
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PMID:Expanded (CAG)n, (CGG)n and (GAA)n trinucleotide repeat microsatellites, and mutant purine synthesis and pigmentation genes cause schizophrenia and autism. 979


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