- Heath Jeffery, Rachael;
- Thompson, Jennifer;
- Lo, Johnny;
- Chelva, Enid;
- Armstrong, Sean;
- Pulido, Jose;
- Procopio, Rebecca;
- Vincent, Andrea;
- Bianco, Lorenzo;
- Battaglia Parodi, Maurizio;
- Ziccardi, Lucia;
- Antonelli, Giulio;
- Barbano, Lucilla;
- Marques, João;
- Geada, Sara;
- Carvalho, Ana;
- Tang, Wei;
- Chan, Choi;
- Boon, Camiel;
- Hensman, Jonathan;
- Chen, Ta-Ching;
- Lin, Chien-Yu;
- Chen, Pei-Lung;
- Vincent, Ajoy;
- Tumber, Anupreet;
- Heon, Elise;
- Grigg, John;
- Jamieson, Robyn;
- Cornish, Elisa;
- Nash, Benjamin;
- Borooah, Shyamanga;
- Ayton, Lauren;
- Britten-Jones, Alexis;
- Edwards, Thomas;
- Ruddle, Jonathan;
- Sharma, Abhishek;
- Porter, Rowan;
- Lamey, Tina;
- McLaren, Terri;
- McLenachan, Samuel;
- Roshandel, Danial;
- Chen, Fred
PURPOSE: To describe the clinical, electrophysiological and genetic spectrum of inherited retinal diseases associated with variants in the PRPH2 gene. METHODS: A total of 241 patients from 168 families across 15 sites in 9 countries with pathogenic or likely pathogenic variants in PRPH2 were included. Records were reviewed for age at symptom onset, visual acuity, full-field ERG, fundus colour photography, fundus autofluorescence (FAF), and SD-OCT. Images were graded into six phenotypes. Statistical analyses were performed to determine genotype-phenotype correlations. RESULTS: The median age at symptom onset was 40 years (range, 4-78 years). FAF phenotypes included normal (5%), butterfly pattern dystrophy, or vitelliform macular dystrophy (11%), central areolar choroidal dystrophy (28%), pseudo-Stargardt pattern dystrophy (41%), and retinitis pigmentosa (25%). Symptom onset was earlier in retinitis pigmentosa as compared with pseudo-Stargardt pattern dystrophy (34 vs 44 years; P = 0.004). The median visual acuity was 0.18 logMAR (interquartile range, 0-0.54 logMAR) and 0.18 logMAR (interquartile range 0-0.42 logMAR) in the right and left eyes, respectively. ERG showed a significantly reduced amplitude across all components (P < 0.001) and a peak time delay in the light-adapted 30-Hz flicker and single-flash b-wave (P < 0.001). Twenty-two variants were novel. The central areolar choroidal dystrophy phenotype was associated with 13 missense variants. The remaining variants showed marked phenotypic variability. CONCLUSIONS: We described six distinct FAF phenotypes associated with variants in the PRPH2 gene. One FAF phenotype may have multiple ERG phenotypes, demonstrating a discordance between structure and function. Given the vast spectrum of PRPH2 disease our findings are useful for future clinical trials.