Characterising PRPF31-associated retinal dystrophy: Clinical insights from baseline data in a natural history study

To characterise the baseline clinical features and genotypes of adults with pre-mRNA processing factor 31 (PRPF31)-associated retinal dystrophy (RD) enrolled in a prospective, multicentre 4-year natural history study, and to explore correlations between selected baseline parameters.

Thirty-one patients with PRPF31-RD underwent comprehensive multimodal assessment, including slit-lamp ophthalmoscopy, best-corrected visual acuity (BCVA), low-luminance visual acuity (LLVA), mesopic and scotopic microperimetry (MP), full-field stimulus threshold (FST) testing, spectral-domain optical coherence tomography (SD-OCT) to assess retinal structure and measure ellipsoid zone (EZ) width, and ultra-widefield fundus autofluorescence (UWF-FAF) to define hyperautofluorescent ring (HAR) area. Correlations between structural and functional measures were analysed using Spearman's rank correlation.

Patients from 21 families carrying 17 distinct disease-causing variants in the PRPF31 gene were identified. The median age was 38 years (range 19-84). Thirty patients exhibited a classic retinitis pigmentosa (RP) phenotype, and one had a pericentral pattern of dystrophy. Frequent findings included cystoid macular oedema (52%), epiretinal membrane (55%) and current or prior cataract (71%). Most patients could complete FST (84%-90%) and mesopic MP testing (77%), while measures of scotopic MP (57%), HAR area (52%) and EZ (68%) excluded the more advanced-staged patients. The HAR area correlated strongly with the functional measures mesopic MP and FST white. The HAR area, EZ width and scotopic MP were also strongly correlated.

This study confirms phenotypic variability in PRPF31-RD and expands the spectrum with pericentral RD. The feasibility of structural and functional assessments depended on disease stage, with scotopic cyan MP limited to eyes with preserved HAR and EZ.