Clinical Features of Autosomal Dominant Retinitis Pigmentosa Associated with a Rhodopsin Mutation (original) (raw)

Graefe's Archive for Clinical and Experimental Ophthalmology Retinal histopathology in eyes from patients with autosomal dominant retinitis pigmentosa caused by rhodopsin mutations

Purpose To evaluate the histopathology in donor eyes from patients with autosomal dominant retinitis pigmentosa (ADRP) caused by p.P23H, p.P347T and p.P347L rhodopsin (RHO) gene mutations. Methods Eyes from a 72-year-old male (donor 1), an 83-yearold female (donor 2), an 80-year-old female (donor 3), and three age-similar normal eyes were examined macroscopically, by scanning laser ophthalmoscopy and optical coherence tomography imaging. Perifoveal and peripheral pieces were processed for microscopy and immunocytochemistry with markers for photoreceptor cells. Results DNA analysis revealed RHO mutations c.68C>A (p.P23H) in donor 1, c.1040C>T (p.P347L) in donor 2 and c.1039C>A (p.P347T) in donor 3. Histology of the ADRP eyes showed retinas with little evidence of stratified nuclear layers in the periphery and a prominent inner nuclear layer present in the perifoveal region in the p.P23H and p.P347T eyes, while it was severely atrophic in the p.P347L eye. The p.P23H and p.P347T mutations cause a profound loss of rods in both the periphery and perifovea, while the p.P347L mutation displays near complete absence of rods in both regions. All three rhodopsin mutations caused a profound loss of cones in the periphery. The p.P23H and p.P347T mutations led to the presence of highly disorganized cones in the perifovea. However, the p.P347L mutation led to near complete absence of cones also in the perifovea. Conclusions Our results support clinical findings indicating that mutations affecting residue P347 develop more severe phenotypes than those affecting P23. Furthermore, our results indicate a more severe phenotype in the p.P347L retina as compared to the p.P347T retina.

Genetic Analysis of the Rhodopsin Gene Identifies a Mosaic Dominant Retinitis Pigmentosa Mutation in a Healthy Individual

Investigative ophthalmology & visual science, 2016

Retinitis pigmentosa (RP) is a group of clinically and genetically heterogeneous hereditary retinal diseases that result in blindness due to photoreceptor degeneration. Mutations in the rhodopsin (RHO) gene are the most common cause of autosomal dominant RP (adRP) and are responsible for 16% to 35% of adRP cases in the Western population. Our purpose was to investigate the contribution of RHO to adRP in the Israeli and Palestinian populations. Thirty-two adRP families participated in the study. Mutation detection was performed by whole exome sequencing (WES) and Sanger sequencing of RHO exons. Fluorescence PCR reactions of serially diluted samples were used to predict the percentage of mosaic cells in blood samples. Eight RHO disease-causing mutations were identified in nine families, with only one novel mutation, c.548-638dup91bp, identified in a family where WES failed to detect any causal variant. Segregation analysis revealed that the origin of the mutation is in a mosaic health...