TY - JOUR
T1 - Phenotypes in defined genotypes including siblings with usher syndrome
AU - Malm, Eva
AU - Ponjavic, Vesna
AU - Möller, Claes
AU - Kimberling, William J.
AU - Andréasson, Sten
N1 - Funding Information:
We thank Ing-Marie Holst and Boel Nilsson for their skillful technical assistance. This study was supported by grants from Söderbergs Forskningsfond, the Swedish Medical Research Council (project no. 2007–3385) and the Foundation Fighting Blindness, Owings Mills, Maryland, USA.
PY - 2011/6
Y1 - 2011/6
N2 - Objective: To characterize visual function in defined genotypes including siblings with Usher syndrome. Methods: Thirteen patients with phenotypically different subtypes of Usher syndrome, including 3 families with affected siblings, were selected. Genetic analysis and ophthalmological examinations including visual fields, full-field electroretinography (ERG), multifocal electroretinography (mf ERG), and optical coherence tomography (OCT) were assessed. The patients' degree of visual handicap was evaluated by a questionnaire (ADL). Results: Twelve of thirteen patients were genotyped as Usher 1B, 1D, 1F, 2A, 2C or 3A. In 12 of 13 patients examined with ERG the 30 Hz flickering light response revealed remaining cone function. In 3 of the patients with Usher type 1 mf ERG demonstrated a specific pattern, with a sharp distinction between the area with reduced function and the central area with remaining macular function and normal peak time. OCT demonstrated loss of foveal depression with distortion of the foveal architecture in the macula in all patients. The foveal thickness ranged from 159 to 384 μm and was not correlated to retinal function. Three siblings shared the same mutation for Usher 2C but in contrast to previous reports regarding this genotype, 1 of them diverged in phenotype with substantially normal visual fields, almost normal OCT and mf ERG findings, and only moderately reduced rod and cone function according to ERG. Conclusions: Evaluation of visual function comprising both the severity of the rod cone degeneration and the function in the macular region confirm phenotypical heterogeneity within siblings and between different genotypes of Usher syndrome.
AB - Objective: To characterize visual function in defined genotypes including siblings with Usher syndrome. Methods: Thirteen patients with phenotypically different subtypes of Usher syndrome, including 3 families with affected siblings, were selected. Genetic analysis and ophthalmological examinations including visual fields, full-field electroretinography (ERG), multifocal electroretinography (mf ERG), and optical coherence tomography (OCT) were assessed. The patients' degree of visual handicap was evaluated by a questionnaire (ADL). Results: Twelve of thirteen patients were genotyped as Usher 1B, 1D, 1F, 2A, 2C or 3A. In 12 of 13 patients examined with ERG the 30 Hz flickering light response revealed remaining cone function. In 3 of the patients with Usher type 1 mf ERG demonstrated a specific pattern, with a sharp distinction between the area with reduced function and the central area with remaining macular function and normal peak time. OCT demonstrated loss of foveal depression with distortion of the foveal architecture in the macula in all patients. The foveal thickness ranged from 159 to 384 μm and was not correlated to retinal function. Three siblings shared the same mutation for Usher 2C but in contrast to previous reports regarding this genotype, 1 of them diverged in phenotype with substantially normal visual fields, almost normal OCT and mf ERG findings, and only moderately reduced rod and cone function according to ERG. Conclusions: Evaluation of visual function comprising both the severity of the rod cone degeneration and the function in the macular region confirm phenotypical heterogeneity within siblings and between different genotypes of Usher syndrome.
KW - Electroretinography
KW - Optical coherence tomography
KW - Usher syndrome
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U2 - 10.3109/13816810.2010.536064
DO - 10.3109/13816810.2010.536064
M3 - Article
C2 - 21174530
AN - SCOPUS:79955809485
SN - 1381-6810
VL - 32
SP - 65
EP - 74
JO - Ophthalmic genetics
JF - Ophthalmic genetics
IS - 2
ER -