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)

The preliminary results based on a three year retrospective study in cavus foot deformity of forty-four Friedreich ataxia patients regularly seen at the Neuromuscular Disease Clinic of Sainte-Justine Hospital have been presented. An accurate "weight-bearing" foot stereoradiographic technique has been recently developed by our group. Since the follow-up period with this device is not sufficient to provide statistical information, the conventional non-weight bearing technique has been utilized in this study to enable a possible comparison between the radiographs of ambulant and non-ambulant patients. Due to the present technique, the results of this study must be interpreted with caution. For 132 pairs of radiographs, 28 parameters have been analyzed. Four of these, namely the calcaneal inclination angle, the first metatarsal inclination angle, the inferior cortex of calcaneus-first metatarsal angle and the first-fifth metatarsals angle, were of particular interest. From these parameters, a preliminary quantitative description of cavus foot deformity in Friedreich's ataxia has been attempted. Three stages of evolution have been tentatively identified for this type of neurological disorder.
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PMID:Roentgenographic study of cavus foot deformity in Friedreich ataxia patients: preliminary report. 710 76

We performed behavioral audiometric tests and brainstem auditory evoked potentials in four patients with Friedreich ataxia. None of the patients had symptomatic hearing difficulties. Results of the audiometric tests pointed to a disorder of the eighth nerve. In none of the patients could we elicit normal-appearing waves of the brainstem auditory evoked potentials. These abnormalities could be attributed to degeneration of spiral ganglion neurons. Our patients had useful and functional hearing despite very abnormal brainstem auditory evoked potentials.
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PMID:Auditory dysfunction in Friedreich ataxia: result of spiral ganglion degeneration. 719 95

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

Polarographic assays of oxidative phosphorylation in muscle mitochondria indicated abnormal pyruvate-malate metabolism in Friedreich ataxia (FA). Pursuing this clue, more specific assays were performed. Mitochondrial malic enzyme (MEm; malate: NADP+ oxidoreductase) specific activity was 10% of controls in fibroblasts from eight FA patients (p less than 0.0001). Cytosolic malic enzyme was modestly increased in FA fibroblasts. Mitochondrial and cytosolic malate dehydrogenase and aspartate aminotransferase, and malate transport on the dicarboxylate and alpha-ketoglutarate carriers were normal in fibroblasts or leukocytes. MEm activity is normally highest in the nervous system and heart is important in regulating carbohydrate metabolism. MEm deficiency could cause FA; further studies are required to substantiate this hypothesis.
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PMID:Friedreich ataxia: III. Mitochondrial malic enzyme deficiency. 719 31

The preliminary results based on a one year study on the evolution and management of scoliosis are presented. Twenty-one patients were followed in the Neuro-Muscular Disease Clinic at Ste-Justine Hospital where standardized spinal radiographs were taken periodically with the Scoliosis Chariot and the Throne. The short period of observation as well as the relatively small number of Friedreich ataxia patients followed requires that these results and the following remarks be interpreted with caution. Pathomechanics -- Between the age groups I (5 - 10 years) and II (10 - 15 years), a substantial increase in the Cobb values occurs. Associated with it, an increase was observed in the thoracic and thoracolumbar projected surface area indices. The relative rotation between the thoracic and lumbar segments was presumed to be the cause of the sudden increase in the Cobb measurements. For the non-ambulatory patients, a decrease in the lumbar lordosis towards a thoraco-lumbar kyphosis as well as a sudden increase in the sacral angle and a drop in the lumbo-sacral angle were associated with the seated posture assumed by the patient. Management -- Prevention of the progression of established curves was our main objective. Careful examination of the spine, depending on the age of the child, in our preliminary study, stimulated early orthopaedic treatment in any curve of 20 degrees or more. There was always concern for curves of 30 degrees or more. In the growing child, bracing was recommended. In the older child, the curve was usually stable after sixteen years of age. Surgery was usually attempted in curves over 40 degrees in the growing child. The same curve was usually stable after the growth period. For the non-ambulatory patients, the present study suggested the prescription of a molded seat with the following characteristics: i) a posterior lumbar support, ii) low thoracic lateral supports and iii) a slight inclination of the seating system. This was presumed to be beneficial in maintaining stability of the spine. Presently, an evaluation of such a device is under investigation.
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PMID:Pathomechanics and management of scoliosis in Friedreich ataxia patients: preliminary report. 721 53

Nerve conduction studies have been performed in 19 subject with hereditary spinocerebellar degenerations other than Friedreich ataxia. Clinically, they may be classified as olivopontocerebellar atrophy or cerebello-olivary degeneration. In 9 patients, sensory conduction was abnormal, and in the whole group there was a significant impairment of sensory conduction and mild slowing of motor conduction in the lateral popliteal nerve. Sural nerve biopsies were performed on 5 patients. In 3 cases there was a mild to moderate reduction of myelinated fibers of all diameters; unmyelinated fibers were normal. In 1 patient from a kindred with a spinocerebellar degeneration in which the inheritance was autosomal dominant, neuropathological findings at autopsy confirmed the clinical diagnosis of the Menzel type of olivopontocerebellar atrophy; there was a degeneration of dorsal root ganglion and anterior horn cells as well as of myelinated fibers of all diameters in the sural nerve.
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PMID:Peripheral neuropathy in spinocerebellar degenerations. 723 46

By analysis of crossovers in key recombinant families and by homozygosity analysis of inbred families, the Friedreich ataxia (FRDA) locus was localized in a 300-kb interval between the X104 gene and the microsatellite marker FR8 (D9S888). By homology searches of the sequence databases, we identified X104 as the human tight junction protein ZO-2 gene. We generated a large-scale physical map of the FRDA region by pulsed-field gel electrophoresis analysis of genomic DNA and of three YAC clones derived from different libraries, and we constructed an uninterrupted cosmid contig spanning the FRDA locus. The cAMP-dependent protein kinase gamma-catalytic subunit gene was identified within the critical FRDA interval, but it was excluded as candidate because of its biological properties and because of lack of mutations in FRDA patients. Six new polymorphic markers were isolated between FR2 (D9S886) and FR8 (D9S888), which were used for homozygosity analysis in a family in which parents of an affected child are distantly related. An ancient recombination involving the centromeric FRDA flanking markers had been previously demonstrated in this family. Homozygosity analysis indicated that the FRDA gene is localized in the telomeric 150 kb of the FR2-FR8 interval.
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PMID:The Friedreich ataxia critical region spans a 150-kb interval on chromosome 9q13. 748 55

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

Friedreich ataxia is a neurodegerative disorder with autosomal recessive inheritance. Since the gene causing mutation has not yet been identified, prenatal, predictive, and carrier diagnoses are based on indirect haplotype analysis with closely linked markers. Until recently, only distal markers were available and their physical distance to the Friedreich ataxia (FRDA) gene remained elusive. The identification of close flanking markers that mark out the boundaries of the FRDA locus and reduce the critical genomic region which contains the gene allows for the first time misdiagnosis due to undetectable recombination to be avoided and diagnosis accuracy to be greatly improved. In this sense, we have verified a prenatal diagnosis in which the fetus was diagnosed as an unaffected carrier last year with a confidence of 95 per cent. By using the new flanking markers, the diagnosis improved and confidence reached almost 100 per cent.
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PMID:Prenatal diagnosis of Friedreich ataxia: improved accuracy by using new genetic flanking markers. 765 88

Friedreich ataxia (FRDA) is an autosomal recessive degenerative disorder that affects the cerebellum, spinal cord, and peripheral nerves. The FRDA gene was localized in 9q13-q21 within 0.7 centimorgan of the D9S5 and D9S15 loci. One recently reported recombination event and haplotype analysis in a population with a founder effect suggested that the FRDA locus is on the D9S5 side. Using a conserved probe from the D9S5 locus, we have now identified an approximately 7-kilobase (kb) transcript and report cloning of its cDNA. The corresponding gene, X11, extends at least 80 kb in a direction opposite D9S15. The gene is expressed in the brain, including the cerebellum, but is not detectable in several nonneuronal tissues and cell lines. In situ hybridization of adult mouse brain sections showed prominant expression in the granular layer of the cerebellum. Expression was also found in the spinal cord. The cDNA contains an open reading frame encoding a 708-amino acid sequence that shows no significant similarity to other known proteins but contains a unique, 24-residue-long, putative transmembrane segment. On the basis of its genomic localization and its neuronal site of expression, particularly in the cerebellum, this "pioneer" gene represents a candidate for FRDA. Direct evidence of its involvement in FRDA will require a search for causative point mutations in patients.
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PMID:Gene in the region of the Friedreich ataxia locus encodes a putative transmembrane protein expressed in the nervous system. 767 31


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