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)

Cranial computerized tomography was carried out in 69 patients with cerebellar ataxia (45 with Friedreich's ataxia, 4 with Marie's spastic ataxia, 14 with cerebellar atrophy, and one patient with olivo-pontocerebellar atrophy). In CT scans cerebellar atrophy is found to be of various localisation and partially of characteristic distribution. CT, therefore, greatly helps to distinguish different types of cerebellar and spino-cerebellar atrophy and also distinguishes separate cerebellar atrophy of various origin from other diseases like multiple sclerosis.
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PMID:[Computerized tomography in atrophy of the posterior fossa (author's transl)]. 744 80

Visual involvement was assessed in 21 patients with Friedreich's ataxia and in 17 patients with spastic ataxia by neuro-ophthalmic examination and by recording visual evoked responses (VERs). Two thirds of the patients with Friedreich's ataxia had some degree of visual impairment and an abnormal VER, whereas only three of the 17 patients with spastic ataxia showed abnormalities. The patients with Friedreich's ataxia could be subdivided into two groups, one with and the other without visual involvement; there was no correlation between the presence and severity of visual involvement and age or duration of symptoms in the group as a whole. Patients with the most severe degrees of visual impairment usually had flat VERs, whereas in less severely affected cases, the responses were reduced in amplitude, were delayed, and showed an increased degree of temporal dispersion. The findings have pathophysiological implications and raise the question of heterogeneity in Friedreich's ataxia.
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PMID:Visual involvement in Friedreich's ataxia and hereditary spastic ataxia. A clinical and visual evoked response study. 746 40

The jaw movement kinematics in relation to the EMG activity of two antagonistic jaw muscles (the masseter and the digastricus pars anterior) were examined in healthy subjects and patients with Friedreich's disease. Dysarthria and ataxia are the main characteristics of this disease. Jaw movement was monitored with a magnetometer system, and bipolar surface electrodes were used to record EMG activity. Unidirectional opening, unidirectional closing and opening-closing movements of the mandible were performed in a simple reaction time situation. The data were compared with those for normal control subjects. The kinematic and electromyographic characteristics were: (a) prolonged total movement duration resulting from increased acceleration and deceleration durations; (b) decreased maximum velocity, and a secondary peak in the velocity profile; (c) tonic EMG activity in muscles supposedly at rest; (d) prolonged EMG bursts. Premotor reaction time was also increased. These characteristics are similar to those, previously described, of limb movements in subjects with cerebellar dysfunctions and suggest that the alterations of jaw movement in Friedreich's ataxia could be due to a deficit in cerebellar control.
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PMID:Biomechanical analysis of simple jaw movements in Friedreich's ataxia. 753 18

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

The most common autosomal recessive ataxia is Friedreich's ataxia (FA), characterized mainly by an early onset, absent tendon reflexes, deep sensory loss, cerebellar and Babinski signs. Screening the patients from families with classical FA features, we found that some families were excluded from the FA locus on chromosome 9, and are associated to isolate vitamin E deficiency. The similarity of the clinical data between FA with and without vitamin E deficiency was remarkable. The disorder with vitamin E deficiency often confused with FA, is currently known as linked to chromosome 8q. Therefore it is important to test vitamin E levels in all patients suspected to have FA, since the alpha tocopherol supplementation may be efficient in early stages of the disease.
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PMID:Friedreich's ataxia-vitamin E responsive type. The chromosome 8 locus. 761 93

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

Friedreich's ataxia is one of the best defined and most common forms of hereditary ataxia of unknown aetiology. It is transmitted in an autosomal recessive manner, appearing sporadically, usually in childhood or adolescence. The case of an elderly patient with a possible diagnosis of late-onset Friedreich's ataxia is reported; this is thought to be the only such case in the literature. The 91-year-old Anglo female presented with ataxia that had been progressive over the last 5 years. Magnetic resonance imaging scans of the head revealed mild peripheral cerebellar atrophy and moderate cerebral atrophy. The patient's parents were unaffected but two of her six siblings had had Friedreich's ataxia starting in childhood, and four of her grandfather's siblings had had an undiagnosed illness that left them in wheelchairs early in life. Friedreich's ataxia was diagnosed in view of the strong family history and non-revealing magnetic resonance imaging of the brain.
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PMID:Friedreich's ataxia in the elderly. 777 61

This review summarizes recent advances that have taken place in the field of inherited ataxias. There is increasing understanding of these disorders, primarily because of advances in the field of molecular genetics. Although the Friedreich's ataxia gene has not been cloned yet, there is increasing information about the precise location of this mutation. The chromosomal location for a distinct type of recessive ataxia associated with vitamin E deficiency was discovered. An adult- onset Friedreich's phenotype may result from a gene abnormality of the same locus as classic Friedreich's ataxia. Two distinct types of dominantly inherited ataxic syndromes are due to different trinucleotide repeat mutations, one on chromosome 6 (spinocerebellar ataxia type 1) and another on chromosome 12 (dentatorubropallidoluysian atrophy). The genes for Machado-Joseph disease as well as for a distinct type of dominantly inherited ataxia originally described from Cuba were mapped to chromosome 14 and chromosome 12, respectively. Advances were made in defining the imaging abnormalities seen in different types of ataxias.
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PMID:Degenerative ataxias. 795 39

This paper reviews the features and topodiagnostical meaning of pathological body posture in cerebellar disorders and presents knowledge as to the physiology and pathophysiology of postural disturbances attributed to the cerebellum. Lesions of the spinocerebellar (upper vermal and intermediate) part of the anterior lobe lead to spontaneous anterior-posterior body sway, with a frequency of about 3 Hz with mild or absent ataxia of the upper limbs, but prominent ataxia of the lower limbs. The tremor is provoked by eye closure and by body displacement. Increased gain and poor cerebellar control of the duration and gain of stabilizing reflexes may be the mechanisms of this oscillation. Lesions of the lower (vestibulocerebellar) vermis cause postural ataxia of the head and trunk while sitting, standing, and walking. Postural ataxia is omnidirectional, sometimes of excessive amplitude and contains frequency components below 1 Hz. Dysmetria of the upper and lower limbs is not prominent. Visual stabilization is less than in the other groups of cerebellar patients. Lesions of the cerebellar hemispheres alone, do not cause an increase of postural sway. Lesions of spinocerebellar afferents (Friedreich's disease) lead to a low frequency large amplitude lateral sway with the most of its power below 1.1 Hz. Visual stabilization is preserved. Latencies of early and late EMG responses to sudden displacements are normal in patients with cerebellar disorders. The cerebellum is, therefore, unlikely to be the primary generator of these reflexive responses. On the other hand, the temporal composition of the orderly time sequence of a complex motor program--be it a voluntary act or its postural balancing--is deranged in cerebellar lesions. It is hypothesized that the cerebellum helps to coordinate the timing not only within but also between the single components involved in each subunit of a complex movement in three-dimensional space and that is scales the size and duration of each muscular action. The cerebellum possibly specifies the cortical movement command and sends it back to the motor cortex. The basic structure of a motor program, however, does not seem to be generated within the cerebellum.
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PMID:Compartmentalized cerebellar functions upon the stabilization of body posture. 809 Oct 78

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


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