Phenotypes in defined genotypes including siblings with usher syndrome

Eva Malm, Vesna Ponjavic, Claes Möller, William J. Kimberling, Sten Andréasson

    Research output: Contribution to journalArticlepeer-review

    22 Scopus citations


    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.

    Original languageEnglish (US)
    Pages (from-to)65-74
    Number of pages10
    JournalOphthalmic genetics
    Issue number2
    StatePublished - Jun 2011


    • Electroretinography
    • Optical coherence tomography
    • Usher syndrome

    ASJC Scopus subject areas

    • Pediatrics, Perinatology, and Child Health
    • Ophthalmology
    • Genetics(clinical)


    Dive into the research topics of 'Phenotypes in defined genotypes including siblings with usher syndrome'. Together they form a unique fingerprint.

    Cite this