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)

The majority of patients with Friedreich ataxia present with gait ataxia. Congestive heart failure usually is a terminal event. We report a 9-year-old boy who developed congestive heart failure and thrombus formation in the left ventricle at age 5 years and then progressive ataxia as well as other features of Friedreich ataxia; therefore, congestive heart failure and thrombus formation may rarely be the initial findings in Friedreich ataxia.
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PMID:Congestive heart failure and cardiac thrombus as first presentations of Friedreich ataxia. 138 25

Sixty-eight human fibroblast cell strains were assayed for radioresistant DNA synthesis (RDS), which is defined here as the absence of a steep component of inhibition of DNA synthesis in a dose-response curve when rate of DNA synthesis is plotted against radiation doses from 0 to 20 Gy or more. Twenty-seven strains from patients who were previously diagnosed to have ataxia-telangiectasia (AT) were positive for this feature. Among the cell strains that did not show RDS were two from AT obligate heterozygotes (i.e., the parents of AT patients), two from patients with Alzheimer disease, two from patients with Friedreich ataxia, one from a patient with Bloom syndrome, one from a patient with Down syndrome, and six from patients with various immunodeficiencies. Four strains demonstrated RDS that was less pronounced than in most AT cells: one was from a patient with Nijmegen breakage syndrome, one was from a patient without ataxia but with choreiform movement disorder, telangiectasia, and elevated concentrations of alpha-fetoprotein in the blood, and two were from AT patients. RDS therefore is not a necessary trait of human genetic diseases that involve radiosensitivity or immunodeficiency. Although recent reports suggest that some AT patients do not exhibit RDS, we found RDS in all the AT cells we tested.
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PMID:Radioresistant DNA synthesis and human genetic diseases. 272 85

The activity of lipoamide dehydrogenase was abnormally heat-labile in homogenized platelets from seven patients with as recessive ataxia conforming to the syndrome of Friedreich ataxia or clinical variants. Taken together, the abnormality and previous findings of low activity and abnormal kinetic properties are compatible with a change in the conformation of the enzyme in these patients.
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PMID:Lipoamide dehydrogenase: rapid heat inactivation in platelets of patients with recessively inherited ataxia. 689 19

Hexosaminidase deficiency diseases or GM2-gangliosidoses were originally described as infantile encephalopathies. Recently, hexosaminidase deficiencies have been found with different phenotypes, including juvenile and adult encephalopathies, cerebellar ataxias, and motor neuron diseases. Individual cases have resembled Ramsey-Hunt syndrome, olivopontocerebellar ataxia, Friedreich ataxia, amyotrophic lateral sclerosis, Kugelberg-Welander disease, Fazio-Londe disease, and Charcot-Marie-Tooth disease. Tremor, dystonia, spastic paresis, and psychosis have been seen. Since few diagnosable causes for these system atrophies are known, these patients should be tested for hexosaminidase deficiency. These recessive disorders fit a multiple loci/multiple alleles genetic scheme, and a clinical genetic classification is presented.
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PMID:The clinical spectrum of hexosaminidase deficiency diseases. 719 92

Friedreich ataxia is an autosomal recessive ataxia with onset usually before puberty whose characteristic clinical features include progressive ataxia of gait and limbs, dysarthria, loss of joint position and vibratory sense, absent knee and ankle jerks, and Babinski signs. Foot deformity, scoliosis, diabetes mellitus, and cardiac involvement are common and characteristic. Patients survive until about age 30 years although longer survivals occur. A later onset, more slowly progressive form seems to be an allelic variant. The basic process seems to be a dying-back of neuronal processes. Using linkage mapping techniques, the classical form of Friedreich ataxia has been localized to 9q13-q21, a region on the long arm of chromosome 9. Haplotype analysis, analysis of recombinants, and physical mapping techniques, including construction of a YAC contig, have narrowed the interval for the Friedreich ataxia gene, FRDA, to a few hundred thousand base pairs. Candidate genes in the region are being studied by techniques of mutation analysis. It is likely that the Freidreich ataxia gene will be cloned soon. A condition resembling Friedreich ataxia with decreased vitamin E levels has been localized to chromosome 8 and is discussed elsewhere.
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PMID:Friedreich ataxia. 761 92

Ataxia with vitamin E deficiency (AVED) is an autosomal recessive disease characterized clinically by neurological symptoms with often striking resemblance to those of Friedreich ataxia. This disorder has been reported previously as familial isolated vitamin E deficiency. We have mapped recently the AVED locus to a 5-cM confidence interval on chromosome 8q by homozygosity mapping in six Mediterranean families. We have now analyzed six new and two previously described families and demonstrate genetic homogeneity despite important clinical variability and wide geographic origins. Analysis of nine new tightly linked microsatellite markers, including four characterized in this study, revealed a predominant but not unique mutation in northern African populations, where this condition is more frequent. Haplotype analysis but also classical recombinations allowed us to refine the AVED position to a 1-cM interval. A YAC contig over this interval was constructed from marker STSs and YAC fingerprint data, in order to facilitate the search of the AVED gene.
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PMID:Ataxia with vitamin E deficiency: refinement of genetic localization and analysis of linkage disequilibrium by using new markers in 14 families. 772 67

Linkage studies with DNA polymorphic markers allowed to map the loci of three inherited ataxia and to explore genetic heterogeneity in inherited ataxia in general. The locus of Friedreich ataxia, the most frequent of all recessive ataxias, has been mapped in 9q13-q21. In addition, Friedreich ataxia is an homogeneous genetic entity since all families from all populations tested (mainly European, North-American and from the Mediterranean basin) show linkage with this locus. But the severity of the disease varied in a few families. A form of recessive ataxia associated with a selective and severe serum vitamin E deficiency, which frequently presents clinically like typical Friedreich ataxia, is not linked to 9q13-q21 markers. The autosomal recessive spastic ataxia from Charlevoix-Saguenay (a region of Quebec) is also not linked to these markers. Both entities are therefore distinct genetically from Friedreich ataxia. Among dominant ataxias, the most important group is olivo-ponto-cerebellar ataxia which is heterogeneous and for which any classification is hindered by important intra-familial variability. This group corresponds to at least three distinct loci, two of which have been mapped, one in 6p23-p24, and the other, more recently, on chromosome 12. Prenatal and presymptomatic diagnosis based on linked markers can be made for the three mapped ataxias, but only in families with an affected individual for whom the diagnosis has been ascertained by through clinical investigation or by linkage analysis if the family is large enough (mainly for the dominant diseases). Linked markers are also the first tools for the search of the defective genes by positional cloning.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Molecular genetics and familial ataxia]. 809 Oct 82

Friedreich ataxia and ataxia with selective vitamin E deficiency (AVED) share very similar clinical phenotypes. We have mapped the AVED locus to proximal 8q with only three large consanguinous Tunisian families, representing to our knowledge the first use of homozygosity mapping for primary linkage analysis. Subsequently, three additional families showed linkage with the same markers. A maximum lod score of 17.9 was obtained at theta = 0 for the haplotype D8S260-D8S510, consisting of the two closest markers. With only 6 families, the AVED locus is therefore mapped precisely as illustrated by the lod-1 confidence interval of 2.4 cM on either side of D8S260-D8S510. Isolation of a yeast artificial chromosome contig > 800 kilobases (kb) showed that D8S260 and D8S510 are less than 400 kb apart.
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PMID:Localization of Friedreich ataxia phenotype with selective vitamin E deficiency to chromosome 8q by homozygosity mapping. 825 33

The onset of Friedreich ataxia (FA) was before 10 years of age in 36 out of 95 personally observed patients. We studied the clinical and laboratory findings of these childhood onset patients. Mean onset age +/- SD was 6.3 +/- 2.4 years. Gait and stance ataxia and lower limb areflexia were constant, dysmetria, dysarthria, Babinski sign, pes cavus, scoliosis and decreased vibration sense were present in the majority of patients. Higher occurrence of diabetes in childhood onset cases (25%) was the only statistical difference in comparison with later onset patients. Mean onset age of diabetes was 21.1 +/- 6.9 years and all patients required insulin. ECG was abnormal in 72% of the patients and echocardiographic evidence of hypertrophic cardiomyopathy was found in 43%. Linkage analysis, performed in 10 families, showed no recombination between the polymorphic markers of the 9q13-21.1 region and the disease locus with a peak lod score of 4.21 at a recombination fraction = 0.00.
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PMID:Childhood onset of Friedreich ataxia: a clinical and genetic study of 36 cases. 867 22

The gene for Friedreich ataxia (FRDA), an autosomal-recessive neurodegenerative disease, remains elusive. The current candidate region of about 150 kb lies between loci FR2 and F8101 near the D9S15/D9S5 linkage group at 9q13-21.1. Linkage homogeneity between classical FRDA and a milder, slowly progressive Acadian variant (FRDA-Acad) has been demonstrated. An extended D9S15-D9S5 haplotype (C6) predominates in FRDA-Acad chromosomes from Louisiana. We studied 10 Acadian families from New Brunswick, Canada. In eight families, affected individuals conformed to the clinical description of FRDA-Acad; in one, 2 sibs presented with spastic ataxia (SPA-Acad). In the last family, 2 sibs had FRDA-Acad, and one had SPA-Acad. We found that SPA-Acad is linked to the FRDA gene region. The C6 haplotype and a second major haplotype (B7) were identified. The same ataxia-linked haplotypes segregated with both FRDA-Acad and SPA-Acad in two unrelated families. The parental origins of these haplotypes were different. Our observation of different phenotypes associated with the same combination of haplotypes may point to the influence of the parent of origin on gene expression, indicate the effect of modifier genes, or reflect the presence of different mutations on the same haplotypes. Our findings underline the need to investigate families with autosomal-recessive ataxias for linkage to the FRDA region, despite lack of key diagnostic manifestations such as cardiomyopathy or absent deep-tendon reflexes.
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PMID:Friedreich ataxia in Acadian families from eastern Canada: clinical diversity with conserved haplotypes. 887 Sep 28


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