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Macular Dysfunction and Morphology in Spinocerebellar Ataxia Type 7 (SCA 7)

Hugosson, Therése LU ; Gränse, Lotta LU ; Ponjavic, Vesna LU and Andréasson, Sten LU (2009) In Ophthalmic Genetics1994-01-01+01:00 30(1). p.1-6
Abstract
Purpose: To characterize the clinical phenotype regarding retinal function and macular appearance in patients with spinocerebellar ataxia type 7 (SCA 7), with an emphasis on electrophysiological findings. Methods: Three patients from two Swedish families were given an ophthalmological examination including visual acuity, fundus inspection, Farnsworth's color vision test, Goldmann perimetry, full-field electroretinography (full-field ERG), multifocal electroretinography (mfERG) and optical coherence tomography (OCT). DNA was analyzed with polymerase chain reaction for CAG trinucleotide expansion repeats in the SCA 7 gene. Results: Molecular analysis demonstrated abnormally expanded CAG repeats in the gene for SCA 7, which encodes the... (More)
Purpose: To characterize the clinical phenotype regarding retinal function and macular appearance in patients with spinocerebellar ataxia type 7 (SCA 7), with an emphasis on electrophysiological findings. Methods: Three patients from two Swedish families were given an ophthalmological examination including visual acuity, fundus inspection, Farnsworth's color vision test, Goldmann perimetry, full-field electroretinography (full-field ERG), multifocal electroretinography (mfERG) and optical coherence tomography (OCT). DNA was analyzed with polymerase chain reaction for CAG trinucleotide expansion repeats in the SCA 7 gene. Results: Molecular analysis demonstrated abnormally expanded CAG repeats in the gene for SCA 7, which encodes the protein ataxin-7, thus confirming the diagnosis SCA 7. In the oldest patient very discreet pigmentary changes in the maculae were found, but with that exception the patients had a normal ophthalmoscopic fundus appearance and OCT demonstrated only minor changes. MfERG indicated predominantly central involvement, especially in the early disease stages, which in pace with disease progression extended from the center to the more peripheral areas. Full-field ERG in the oldest patient demonstrated bilaterally distinctly prolonged 30-Hz flicker implicit time, verifying widespread cone photoreceptor degeneration. Conclusions: The patients with genetically confirmed SCA 7 presented an early macular dysfunction, preceding any signs of abnormalities in fundus appearance. According to the electrophysiological findings the primary dysfunction involves the cone photoreceptors in the foveal region, however in an older patient involvement of cone photoreceptors throughout the retina was verified. This is in accordance with the theory that ataxin-7 interacts with CRX transcription, since it is known that mutations in the CRX gene cause cone-rod dystrophy. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
full-field electroretinography (full-field ERG), (mfERG), Spinocerebellar ataxia type 7 (SCA 7), multifocal electroretinography, optical, coherence tomography (OCT)
in
Ophthalmic Genetics1994-01-01+01:00
volume
30
issue
1
pages
1 - 6
publisher
Taylor & Francis
external identifiers
  • wos:000262789600001
  • scopus:61749090887
ISSN
1744-5094
DOI
10.1080/13816810802454081
language
English
LU publication?
yes
id
ca8a4694-be78-4b59-b7ac-2af904a66010 (old id 1312175)
date added to LUP
2009-03-18 08:53:09
date last changed
2017-10-22 04:06:31
@article{ca8a4694-be78-4b59-b7ac-2af904a66010,
  abstract     = {Purpose: To characterize the clinical phenotype regarding retinal function and macular appearance in patients with spinocerebellar ataxia type 7 (SCA 7), with an emphasis on electrophysiological findings. Methods: Three patients from two Swedish families were given an ophthalmological examination including visual acuity, fundus inspection, Farnsworth's color vision test, Goldmann perimetry, full-field electroretinography (full-field ERG), multifocal electroretinography (mfERG) and optical coherence tomography (OCT). DNA was analyzed with polymerase chain reaction for CAG trinucleotide expansion repeats in the SCA 7 gene. Results: Molecular analysis demonstrated abnormally expanded CAG repeats in the gene for SCA 7, which encodes the protein ataxin-7, thus confirming the diagnosis SCA 7. In the oldest patient very discreet pigmentary changes in the maculae were found, but with that exception the patients had a normal ophthalmoscopic fundus appearance and OCT demonstrated only minor changes. MfERG indicated predominantly central involvement, especially in the early disease stages, which in pace with disease progression extended from the center to the more peripheral areas. Full-field ERG in the oldest patient demonstrated bilaterally distinctly prolonged 30-Hz flicker implicit time, verifying widespread cone photoreceptor degeneration. Conclusions: The patients with genetically confirmed SCA 7 presented an early macular dysfunction, preceding any signs of abnormalities in fundus appearance. According to the electrophysiological findings the primary dysfunction involves the cone photoreceptors in the foveal region, however in an older patient involvement of cone photoreceptors throughout the retina was verified. This is in accordance with the theory that ataxin-7 interacts with CRX transcription, since it is known that mutations in the CRX gene cause cone-rod dystrophy.},
  author       = {Hugosson, Therése and Gränse, Lotta and Ponjavic, Vesna and Andréasson, Sten},
  issn         = {1744-5094},
  keyword      = {full-field electroretinography (full-field ERG),(mfERG),Spinocerebellar ataxia type 7 (SCA 7),multifocal electroretinography,optical,coherence tomography (OCT)},
  language     = {eng},
  number       = {1},
  pages        = {1--6},
  publisher    = {Taylor & Francis},
  series       = {Ophthalmic Genetics1994-01-01+01:00},
  title        = {Macular Dysfunction and Morphology in Spinocerebellar Ataxia Type 7 (SCA 7)},
  url          = {http://dx.doi.org/10.1080/13816810802454081},
  volume       = {30},
  year         = {2009},
}