Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0007758 (cerebellar ataxia)
 3,609 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Molecular genetic assessments of 69 individuals in 44 families with hereditary cerebellar ataxia (HCA) were made to determine the relative frequencies of subtypes of HCA in Yamagata, Japan. Fifteen families (34%) had SCA1, none had SCA2, nine (20%) had MJD, five (11%) had SCA6 and nine (20%) had DRPLA. These findings differ markedly from those in other regions of Japan and the rest of the world. A morphometrical study of the brain MR images also was made on 38 individuals with SCA1 (n = 14), MJD (n = 8) or SCA6 (n = 16). In SCA1, the ventral pons was atrophic in proportion to the amount of cerebellar atrophy. In MJD, both the pons and the cerebellum were atrophic, cerebellar atrophy being less pronounced than that in SCA1 and SCA6. While both the major and minor axes of the ventral pons were proportionally decreased in SCA1, the minor axis was more decreased than the major axis in MJD. In SCA6, a mild reduction in the ratio of the ventral pontine area to the posterior fossa area (Pv/PF) was observed as well as obvious cerebellar atrophy. These findings indicate that in MR images SCA1, MJD and SCA6 show different atrophic features of the cerebellum and brainstem.
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PMID:Regional differences in genetic subgroup frequency in hereditary cerebellar ataxia, and a morphometrical study of brain MR images in SCA1, MJD and SCA6. 1040 32

Autosomal dominant cerebellar ataxia type I is the most common form of dominant ataxia. A genetic heterogeneity has been identified with five different loci (SCA1, 2, 3, 4, and 6). A pathological expansion of a CAG sequence has been identified in SCA1, 2, 3, and 6. We performed molecular analysis in 51 families with autosomal dominant cerebellar ataxia type I, mainly originating from southern Italy and Sicily. Thirty families carry an expanded CAG sequence within SCA2 gene. The mean number of repeats was 39.9 +/- 3.3 in 85 expanded alleles, with a range of 34-52. The number of triplets was inversely correlated with age at onset and explained 76% of the variance. The best fit was obtained with an exponential relationship between variables. Expanded alleles were unstable when transmitted from parents to offspring. Expansions were more common than contractions, accounting for 59% of the total meioses and for 80% of the father-child transmissions. The mean intergenerational variation was 1.9 repeats (range -3 to +15) with higher values for male transmissions. Bulbar and autonomic signs were related to disease duration, pyramidal signs to CAG size, cerebellar features and peripheral neuropathy to both. Among the remaining 21 families, three carried the SCA1 and one the SCA6 mutation. This study suggests that SCA2 is the prevalent mutation in southern Italy.
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PMID:Spinocerebellar ataxia type 2 in southern Italy: a clinical and molecular study of 30 families. 1043 73

Pigmentary macular dystrophy (PMD) was detected in a 57-year-old Japanese man with SCA1, five years after the onset of ataxia. Family history revealed 7 other ataxic members in three generations. Among them, only his younger brother, who had already died, had developed central scotoma with normal peripheral fields, 15 years after the ataxia had appeared. None of the other family members, with or without ataxia, had visual disturbances. The numbers of CAG repeats in the patient's SCA1 gene were 27 and 47, the latter of which was within pathological range and belonged to mild to moderate CAG expansion in previously reported cases. The PMD seen in our patient could be one of the clinical features associated with SCA1, since patients with SCA1 often show various ocular changes. Although genetic analysis ruled out SCA7 in this patient, the phenotypic resemblance of this patient to SCA7 may reflect the necessity in the future, for genetic differentiation between SCA1 and SCA7 in patients with autosomal dominant cerebellar ataxia and PMD.
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PMID:[A family of SCA1 with pigmentary macular dystrophy]. 1050 91

Forty-six patients suffering from autosomal dominant cerebellar ataxia type I (ADCA I) underwent to a genotype-phenotype correlation analysis by molecular genetic assignment to the spinocerebellar ataxia type 1, 2, or 3 (SCA1, SCA2, SCA3) genetic locus and electro-oculography. Oculomotor deficits that are attributed to dysfunction of cerebellar structures occurred in all three mutations without major differences between the groups. Gaze-evoked nystagmus, however, was not found to be associated with SCA2. Square wave jerks were exclusively observed in SCA3. The gain in vestibulo-ocular reflex was significantly impaired in SCA3 and SCA1. In SCA3 the severity of vestibular impairment increased with CAG repeat length. Severe saccade slowing was a highly characteristic feature of SCA2. In SCA3 saccade velocity was normal to mildly reduced while SCA1 fell into an intermediate range. The present data show that each mutation is associated with a distinct syndrome of oculomotor deficits. Reduced saccade velocity and the absence of both square-wave jerks and gaze-evoked nystagmus allow one SCA2 to be distinguished from SCA3 patients in almost all cases. The eye movement disorder of SCA1 patients, however, overlaps with both SCA2 and SCA3.
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PMID:Autosomal dominant cerebellar ataxia type I: oculomotor abnormalities in families with SCA1, SCA2, and SCA3. 1052 76

Autosomal dominant spinocerebellar ataxias (SCA) are a group of clinically and genetically heterogeneous neurodegenerative disorders which lead to progressive cerebellar ataxia. A gene responsible for SCA type 2 has been mapped to human chromosome 12 and the disease causing mutation has been identified as an unstable and expanded (CAG)n trinucleotide repeat. We investigated the (CAG)n repeat length of the SCA2 gene in 842 patients with sporadic ataxia and in 96 German families with dominantly inherited SCA which do not harbor the SCA1 or MJD1/SCA3 mutation, respectively. The SCA2 (CAG)n expansion was identified in 71 patients from 54 families. The (CAG)n stretch of the affected allele varied between 36 and 64 trinucleotide units. Significant repeat expansions occurred most commonly during paternal transmission. Analysis of the (CAG)n repeat lengths with the age of onset in 41 patients revealed an inverse correlation. Two hundred and forty-one apparently healthy octogenerians carried alleles between 16 and 31 repeats. One 50-year old, healthy individual had 34 repeats; she had transmitted an expanded allele to her child. The small difference between 'normal' and disease alleles makes it necessary to define the extreme values of their ranges. With one exception, the trinucleotide expansion was not observed in 842 ataxia patients without a family history of the disease. The SCA2 mutation causes the disease in nearly 14% of autosomal dominant SCA in Germany.
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PMID:SCA2 trinucleotide expansion in German SCA patients. 1073 76

This study aimed to determine if cerebellar ataxia, hypogonadism and chorioretinopathy (AHCR) is associated with mutations in mitochondrial DNA or in genes responsible for spinocerebellar ataxias (SCA1, SCA2, SCA3 and Friedreich's ataxia). Two brothers with cerebellar ataxia, hypogonadism and chorioretinopathy and their unaffected parents underwent molecular analysis for duplications and deletions in mitochondrial DNA (mtDNA), point mutations in the ATP ase 6 gene, and expansions of CAG repeats (at 6p22-p23, 12q24.1, 14q32.1) and of GAA repeats (at gene X25 on chromosome 9q13). The research was negative for all mutations. Our findings confirm that AHCR is a distinct disease within the inherited cerebellar ataxias.
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PMID:Cerebellar ataxia, hypogonadism and chorioretinopathy: molecular analysis of an Italian family. 1093 59

Disease-causing mutations have been identified in various entities of autosomal dominant ataxia and in Friedreich's ataxia. However, no molecular pathogenic factor is known to cause idiopathic cerebellar ataxias. We investigated the CAG/CTG trinucleotide repeats causing spinocerebellar ataxia types 1, 2, 3, 6, 7, 8 and 12, and the GAA repeat of the frataxin gene in 124 patients apparently suffering from idiopathic sporadic ataxia, including 20 patients with the clinical diagnosis of multiple system atrophy. Patients with a positive family history, a typical Friedreich phenotype, or symptomatic ataxia were excluded. Genetic analyses uncovered the most common Friedreich mutation in 10 patients with an age at onset between 13 and 36 years. The SCA6 mutation was present in nine patients with disease onset between 47 and 68 years of age. The CTG repeat associated with SCA8 was expanded in three patients. One patient had SCA2 attributable to a de novo mutation from a paternally transmitted, intermediate allele. We did not identify the SCA1, SCA3, SCA7 or SCA12 mutation in idiopathic sporadic ataxia patients. No trinucleotide repeat expansion was detected in the MSA subgroup. This study has revealed the genetic basis in 19% of apparently idiopathic ataxia patients. SCA6 is the most frequent mutation in late onset cerebellar ataxia. The frataxin trinucleotide expansion should be investigated in all sporadic ataxia patients with onset before age 40, even when the phenotype is atypical for Friedreich's ataxia.
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PMID:Genetic background of apparently idiopathic sporadic cerebellar ataxia. 1103 Apr 10

Spinocerebellar ataxia (SCA) type 7 is an autosomal dominant disorder characterized by neural loss, mainly in the cerebellum and regions of the brainstem and particularly the inferior olivary complex. This neurodegeneration disease is associated with expansion of unstable CAG repeats within the 5'-translated region of the SCA7 gene, located on chromosome 3p. We conducted a local survey of the normal population and candidate patients for the analysis of the CAG repeats in the SCA7 gene. The distributions of the CAG repeat units of SCA7 gene in the normal population in Taiwan were established in this study by using the radioactive genomic polymerase chain reaction (PCR). The normal range of CAG repeats is from 6 to 17 repeats, with the more common being around 8-13 repeats. The range is narrower than that reported for other ethnic groups (7-35 CAGs). Meanwhile, by the use of a combination of PCR and Southern blot analysis, one SCA7 family was identified and is reported here. A marked instability of the CAG repeat number during transmission from father to son (41 vs. 100) was observed in the SCA7 family. Clinical anticipation is significant in this family including an infantile case, who was found to have nystagmus from the age of 1 month. To date, the SCA7 mutation has been detected in one of 73 families with autosomal dominant cerebellar ataxia phenotypes, which is about 1.4% of the ataxia families referred to us, compared to 1.4% SCA1, 9.6% SCA2, and 27.3% SCA3/Machado-Joseph disease in our collection. In addition, we demonstrate that the PCR-based Southern blot analysis, with the advantages of sensitivity of PCR and specificity of Southern blot, is a reliable diagnostic method for SCA7 mutation screening. The molecular analysis technique makes possible the quick and accurate diagnosis of SCA7 patients and in the future will hopefully be applied to prenatal screening for SCA7 families.
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PMID:Identification of the spinocerebellar ataxia type 7 mutation in Taiwan: application of PCR-based Southern blot. 1104 30

In patients with degenerative ataxia, various abnormalities in motor cortex activation by transcranial magnetic stimulation (TMS) have been observed, including a reduction of intracortical facilitation and a lengthening of the silent period. However, the groups of patients examined in previous studies were heterogeneous, involving patients with autosomal-dominant and idiopathic cerebellar ataxia, and showing different clinical features. The aim of our present study was to investigate whether differences in motor cortex activation by TMS could be observed in genetically defined subtypes of degenerative ataxia. We examined six patients with Friedreich's ataxia, three patients with spinocerebellar ataxia (SCA) type 1, seven patients with SCA2, 12 patients with SCA3, nine patients with SCA6 and 14 healthy controls. In all subjects, motor threshold, central motor conduction time, cortical silent period after TMS, and intracortical inhibition and facilitation (as assessed by TMS using a paired pulses paradigm) were determined. Additionally, F wave amplitudes evoked by electrical peripheral nerve stimulation were measured. We found a significant reduction of intracortical facilitation in SCA2 and SCA3 patients. Furthermore, motor threshold was elevated in SCA1, central motor conduction time was lengthened in patients with Friedreich's ataxia and SCA1, and F wave amplitudes were enlarged in all the genetic subgroups except for SCA6. Silent period and intracortical inhibition did not differ between patients and controls. We conclude that changes of intracortical facilitation induced by TMS and other excitability parameters of the motor system are not a common phenomenon in degenerative ataxia, but are restricted to specific subtypes. This points to differences in the underlying pathophysiological processes in genetic subtypes of ataxia.
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PMID:Motor cortex activation by transcranial magnetic stimulation in ataxia patients depends on the genetic defect. 1184 30

The present authors studied a 55-year-old-patient homozygous for the SCA6 gene who experienced frequent attacks of positional vertigo at 37 years of age with subsequent staggering gait and night blindness. Retinitis pigmentosa (RP), as well as cerebellar ataxia and vertical antidirectional nystagmus, were detected. The subject's parents were first cousins, and two of his three male cousins, whose parents were also first cousins, had RP without ataxia or nystagmus. The numbers of CAG repeats in the expanded alleles of the SCA6 gene found by molecular analysis were 21 and 21. The genetic results were negative for SCA1, SCA2, SCA3, SCA7 and dentatorubral pallidoluysian atrophy. The retinal degeneration in this patient is most likely to be secondary to a genetic disorder of autosomal or X-linked recessive inheritance rather than SCA6. Other reported cases of patients homozygous for the SCA6 gene are also reviewed.
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PMID:A patient homozygous for the SCA6 gene with retinitis pigmentosa. 1208 23


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