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Clinical expression of X-linked retinitis pigmentosa in a Swedish family with the RP2 genotype

Ponjavic, Vesna LU ; Andréasson, Sten LU ; Abrahamson, Magnus LU ; Ehinger, Berndt LU ; Gieser, L; Fujita, R and Swaroop, A (1998) In Ophthalmic Genetics 19(4). p.187-196
Abstract
PURPOSE: To examine the clinical phenotype with emphasis on electroretinograms and visual fields in a Swedish family with X-linked retinitis pigmentosa (XLRP) type 2 (RP2), and compare it with Swedish XLRP families with the RP3 genotype. METHODS: Three affected brothers and their carrier mother were examined clinically and with kinetic perimetry, dark adaptation thresholds, and full-field electroretinograms. The genotype was determined by haplotype analysis using polymorphic markers spanning the XLRP loci at the short arm of the X chromosome. RESULTS: The phenotype was consistent in the three affected males. The first subjective symptom was night blindness and the visual disability was more pronounced with increasing age. Affected... (More)
PURPOSE: To examine the clinical phenotype with emphasis on electroretinograms and visual fields in a Swedish family with X-linked retinitis pigmentosa (XLRP) type 2 (RP2), and compare it with Swedish XLRP families with the RP3 genotype. METHODS: Three affected brothers and their carrier mother were examined clinically and with kinetic perimetry, dark adaptation thresholds, and full-field electroretinograms. The genotype was determined by haplotype analysis using polymorphic markers spanning the XLRP loci at the short arm of the X chromosome. RESULTS: The phenotype was consistent in the three affected males. The first subjective symptom was night blindness and the visual disability was more pronounced with increasing age. Affected individuals had a slight decrease in visual acuity and were emmetropic. They demonstrated a pathologically elevated final rod threshold. The visual fields were constricted in a somewhat atypical pattern. The three patients had an early presenting atypical cataract with multiple opacities. The fundus appearance was typical for RP with narrowing of retinal vessels and bone spicule pigmentations. The rod electroretinograms were extinguished in both eyes of the patients. The combined rod-cone responses as well as the isolated cone responses were severely reduced in amplitude; however, atypically for RP, the implicit time for the isolated cone responses was normal. The carrier female demonstrated normal ophthalmological findings, with the exception of two minimal pigmentations in the lower quadrants of the left eye. Haplotype analysis demonstrated that the disease in this family segregates with the RP2 locus. CONCLUSION: The phenotype of the studied RP2 family is associated with early onset of night blindness, emmetropia, a slight decrease in visual acuity, constriction of visual fields, and atypical cataract formation. Electroretinograms demonstrate severe rod dysfunction and surprisingly normal cone response implicit times which may indicate a milder disease progression. These findings are different from earlier descriptions of the RP2 and RP3 phenotypes. (Less)
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author
organization
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type
Contribution to journal
publication status
published
subject
in
Ophthalmic Genetics
volume
19
issue
4
pages
187 - 196
publisher
Taylor & Francis
external identifiers
  • scopus:0032422621
ISSN
1744-5094
language
English
LU publication?
yes
id
d038ea38-9611-47d3-ac0f-b1231ef215ca (old id 1113923)
date added to LUP
2008-07-16 13:56:31
date last changed
2017-01-01 06:57:25
@article{d038ea38-9611-47d3-ac0f-b1231ef215ca,
  abstract     = {PURPOSE: To examine the clinical phenotype with emphasis on electroretinograms and visual fields in a Swedish family with X-linked retinitis pigmentosa (XLRP) type 2 (RP2), and compare it with Swedish XLRP families with the RP3 genotype. METHODS: Three affected brothers and their carrier mother were examined clinically and with kinetic perimetry, dark adaptation thresholds, and full-field electroretinograms. The genotype was determined by haplotype analysis using polymorphic markers spanning the XLRP loci at the short arm of the X chromosome. RESULTS: The phenotype was consistent in the three affected males. The first subjective symptom was night blindness and the visual disability was more pronounced with increasing age. Affected individuals had a slight decrease in visual acuity and were emmetropic. They demonstrated a pathologically elevated final rod threshold. The visual fields were constricted in a somewhat atypical pattern. The three patients had an early presenting atypical cataract with multiple opacities. The fundus appearance was typical for RP with narrowing of retinal vessels and bone spicule pigmentations. The rod electroretinograms were extinguished in both eyes of the patients. The combined rod-cone responses as well as the isolated cone responses were severely reduced in amplitude; however, atypically for RP, the implicit time for the isolated cone responses was normal. The carrier female demonstrated normal ophthalmological findings, with the exception of two minimal pigmentations in the lower quadrants of the left eye. Haplotype analysis demonstrated that the disease in this family segregates with the RP2 locus. CONCLUSION: The phenotype of the studied RP2 family is associated with early onset of night blindness, emmetropia, a slight decrease in visual acuity, constriction of visual fields, and atypical cataract formation. Electroretinograms demonstrate severe rod dysfunction and surprisingly normal cone response implicit times which may indicate a milder disease progression. These findings are different from earlier descriptions of the RP2 and RP3 phenotypes.},
  author       = {Ponjavic, Vesna and Andréasson, Sten and Abrahamson, Magnus and Ehinger, Berndt and Gieser, L and Fujita, R and Swaroop, A},
  issn         = {1744-5094},
  language     = {eng},
  number       = {4},
  pages        = {187--196},
  publisher    = {Taylor & Francis},
  series       = {Ophthalmic Genetics},
  title        = {Clinical expression of X-linked retinitis pigmentosa in a Swedish family with the RP2 genotype},
  volume       = {19},
  year         = {1998},
}