Unilateral retinitis pigmentosa: a proposal of genetic pathogenic mechanisms

PURPOSE. To investigate and integrate anatomic and physiologic findings from a group of patients who present retinitis pigmentosa affecting just one eye and use this information to propose mechanisms of disease pathogenesis. METHODS. This prospective cross-sectional study examined 5 patients, all female, from 8 to 60 years old. The study was conducted in 4 university hospitals. The patients were selected according to the characteristics of ocular involvement, notably unilateral presentation of similar anatomic and functional abnormalities. Full-field electroretinogram, fundus photography, fundus autofluorescence, infrared imaging, optical coherence tomography, and genetic testing were performed. RESULTS. Full-field electroretinogram showed unilateral decrease in amplitude and increase in implicit time; autofluorescence showed unilateral areas of decreased intensity. The USH2AW4149R mutation was confirmed in one patient. CONCLUSIONS. Imaging and functional testing are important in elucidating the unilateral pattern of the disease and in monitoring these individuals. Mosaicism or somatic mutation may cause unilateral genetic disease presentation.