Genetic and clinical characterization of suspected retinitis pigmentosa in a cohort of Brazilian patients

Purpose To identify causative genetic variants and associated clinical phenotypes in patients of a tertiary referral center in Brazil with suspected retinitis pigmentosa (RP). Methods RP diagnosis was established based on predefined clinical criteria. The patients underwent detailed ophthalmologic assessments and multimodal retinal imaging. Genomic DNA was analyzed using a next-generation sequencing (NGS) panel targeting 238 genes associated with inherited retinal diseases. Results Among 55 patients, the genetic diagnostic yield was 71% (39/55), with 13 novel variants identified. The most frequently implicated genes were RHO, RPGR, and USH2A, accounting for approximately 50% of genetically diagnosed cases. Fundus autofluorescence revealed patchy hypoautofluorescence surrounding the vascular arcades as the most frequent finding. On spectral-domain optical coherence tomography, the pattern of ellipsoid zone presentation in the central macula was significantly correlated with best-corrected visual acuity (p<0.001). Conclusions This study delineates the genetic and phenotypic spectrum of RP in a tertiary Brazilian referral center, highlighting the utility of NGS for molecular diagnosis and clinical management.