Abstract
Purpose: :
To study the clinical phenotype with emphasis on macular structure and function in two Swedish families with autosomal dominant retinitis pigmentosa (ad RP) with mutations in the PRPF31 gene or in the RHO135/GUCY2D genes.
Methods: :
Four members of the family with a mutation in the PRPF31 gene, and five members of the family with a mutation/mutations in the RHO135/GUCY2D genes, were examined clinically, including optical coherence tomography (OCT), standardized full-field electroretinography (ERG) and multifocal electroretinography (mf ERG). In addition, molecular genetic analysis of blood samples was performed.
Results: :
The family with a mutation in the PRPF31 gene demonstrated clinical features characteristic for RP with severely reduced retinal function. The mf ERG demonstrated only centrally preserved macular function. This was negatively correlated to increasing age, considered to be the typical RP phenotype. All affected individuals showed a similar pattern of the OCT macular thickness map, which agrees with the pattern for the mf ERG. Concerning the thickness of the RNFL around the optic nerve, all individuals showed normal results for the temporal segment which corresponds to the macular region, while in other segments the pattern was variable. The family horboring a mutation/mutations in the RHO135/GUCY2D genes demonstrated a markedly variable RP phenotype, with mild degenerative changes in the mother who had significant alterations only in the mf ERG, but with severe degeneration in her three children, both in ERG, mf ERG and OCT
Conclusions: :
These two Swedish families with ad RP with mutations in the PRPF31 gene or in the RHO135/GUCY2D genes demonstrate an extremely variable clinical phenotype regarding macular structure and function, which can be affected early in the course of the disease. Methods for evaluation of central retinal function, such as mf ERG and OCT may contribute with important information when added to the standardized ERG, for more detailed characterization of the clinical phenotype.
Keywords: retinal degenerations: hereditary • electroretinography: clinical • retinal degenerations: hereditary