Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Autosomal dominant spinocerebellar ataxia 7 is associated with retinal degeneration. SCA7, the causative gene, encodes ataxin-7, a ubiquitous 892 amino acid protein of variable sub-cellular localization, and the disease is due to expansion of an unstable CAG repeat in the coding region of the gene. Recent increases in understanding of the mechanisms ofSCA7 -related retinopathy from in vitro and murine model studies prompted us to perform a detailed study of the retinal phenotype of affected members of a family with SCA7 mutation (45-47 CAG repeats). There was a spectrum of severity from mild to severe dysfunction. Early functional abnormalities were at both photoreceptor and post-receptoral levels. When cone and rod photoreceptor dysfunction was present, it was approximately equal. Regional retinal dysfunction was evident: there was more dysfunction centrally than peripherally with least effect in the midperiphery. In vivo cross-sectional retinal images with optical coherence tomography showed an early disease stage of altered foveal lamination (abnormal area of low reflectivity splitting the outer retina-choroidal complex) accompanied in the parafovea by reduced retinal thickness. Later disease stages showed foveal and parafoveal retinal thinning. The phenotype in this family with SCA7 is that of a cone-rod dystrophy. These observations increase interest in a recent hypothesis that ataxin-7 may interfere with the function of CRX (cone-rod homeobox), a transcription factor regulating photoreceptor genes and a cause of a cone-rod dystrophy phenotype in man.
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PMID:Spinocerebellar ataxia type 7 (SCA7) shows a cone-rod dystrophy phenotype. 1212 46

Spinocerebellar ataxia type 7 (SCA7) is a dominantly inherited disorder characterized by cerebellum and brainstem neurodegeneration. SCA7 is caused by a CAG/polyglutamine (polyQ) repeat expansion in the ataxin-7 gene. We previously reported that directed expression of polyQ-ataxin-7 in Bergmann glia (BG) in transgenic mice leads to ataxia and non-cell-autonomous Purkinje cell (PC) degeneration. To further define the cellular basis of SCA7, we derived a conditional inactivation mouse model by inserting a loxP-flanked ataxin-7 cDNA with 92 repeats into the translational start site of the murine prion protein (PrP) gene in a bacterial artificial chromosome (BAC). The PrP-floxed-SCA7-92Q BAC mice developed neurological disease, and exhibited cerebellar degeneration and BG process loss. To inactivate polyQ-ataxin-7 expression in specific cerebellar cell types, we crossed PrP-floxed-SCA7-92Q BAC mice with Gfa2-Cre transgenic mice (to direct Cre to BG) or Pcp2-Cre transgenic mice (which yields Cre in PCs and inferior olive). Excision of ataxin-7 from BG partially rescued the behavioral phenotype, but did not prevent BG process loss or molecular layer thinning, while excision of ataxin-7 from PCs and inferior olive provided significantly greater rescue and prevented both pathological changes, revealing a non-cell-autonomous basis for BG pathology. When we prevented expression of mutant ataxin-7 in BG, PCs, and inferior olive by deriving Gfa2-Cre;Pcp2-Cre;PrP-floxed-SCA7-92Q BAC triple transgenic mice, we noted a dramatic improvement in SCA7 disease phenotypes. These findings indicate that SCA7 disease pathogenesis involves a convergence of alterations in a variety of different cell types to fully recapitulate the cerebellar degeneration.
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PMID:Spinocerebellar ataxia type 7 cerebellar disease requires the coordinated action of mutant ataxin-7 in neurons and glia, and displays non-cell-autonomous bergmann glia degeneration. 2207 78

Spinocerebellar ataxia type 7 (SCA7) is a late-onset neurodegenerative disease characterized by ataxia and vision loss with no effective treatments in the clinic. The most striking feature is the degeneration of Purkinje neurons of the cerebellum caused by the presence of polyglutamine-expanded ataxin-7. Ataxin-7 is part of a transcriptional complex, and, in the setting of mutant ataxin-7, there is misregulation of target genes. Here, we designed RNAi sequences to reduce the expression of both wildtype and mutant ataxin-7 to test if reducing ataxin-7 in Purkinje cells is both tolerated and beneficial in an animal model of SCA7. We observed sustained reduction of both wildtype and mutant ataxin-7 as well as a significant improvement of ataxia phenotypes. Furthermore, we observed a reduction in cerebellar molecular layer thinning and nuclear inclusions, a hallmark of SCA7. In addition, we observed recovery of cerebellar transcripts whose expression is disrupted in the presence of mutant ataxin-7. These data demonstrate that reduction of both wildtype and mutant ataxin-7 by RNAi is well tolerated, and contrary to what may be expected from reducing a component of the Spt-Taf9-Gcn5 acetyltransferase complex, is efficacious in the SCA7 mouse.
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PMID:Nonallele specific silencing of ataxin-7 improves disease phenotypes in a mouse model of SCA7. 2493 Jun 1

Background: Spinocerebellar ataxia Type 7 (SCA7) is an autosomal dominant, progressive neurodegenerative disorder, primarily characterized by cerebellar ataxia. The disease is caused by the expansion of a CAG trinucleotide repeat within the ataxin-7 gene when its CAG repeat sequences are extended beyond 38. The degree of retinopathy can vary from pigment change in the fovea to foveal atrophy and is correlated with the number of CAG repeats. The present study describes a case of SCA7 with a retinal presentation similar to occult macular dystrophy (OMD) which is an inherited macular dystrophy characterized by presenting with a normal fundus and fluorescein angiography but with progressive central visual loss. Materials and Methods: Report of a case. Results: In this case, no specific abnormality was found on fundus examination, fluorescein angiography, full-field electroretinography and infrared autofluorescence. Spectral-domain optical coherence tomography showed foveal thinning, focal disruption of the ellipsoid zone, and central loss of the outer segment-retinal pigment epithelium interdigitation zone that were well matched with the multifocal electroretinography finding. Thirty-nine CAG repeats in ataxin-7 gene were identified through genetic testing. Conclusions: SCA7 can present with a very mild form of retinal degeneration similar to the classic phenotype of RP1L1-negative OMD in case of the lower number of CAG repeats.
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PMID:Spinocerebellar ataxia type 7 with RP1L1-negative occult macular dystrophy as retinal manifestation. 3126 56