Clinical characteristics of EYS-associated retinal dystrophy in 291 Japanese patients.

Eyes shut homolog (EYS) is the most common autosomal recessive causative gene of inherited retinal dystrophy (IRD) in the Japanese population, yet genotype-phenotype correlation data remain limited. We analyzed 291 probands (141 males, 150 females) with IRD caused by EYS (EYS-RD) from eight Japanese facilities. Clinical variables included age at onset, initial symptoms, best-corrected visual acuity (BCVA), and its progression alongside genotype information. Mean onset was 25.8 ± 14.9 years, most often night blindness (67.0%), and rod-cone dystrophy was observed in 95.9%. Initial BCVA averaged 0.34 ± 0.56 logMAR, declining 0.03 ± 0.06 logMAR/year, with low vision and blindness estimated at 48.4 and 73.6 years, respectively. Three major East Asian-specific pathogenic variants (S1653fs, Y2935X, and G843E) accounted for 88.7% of all cases. S1653fs homozygotes showed the earliest onset (mean, 18.4 years). These findings support the potential of genetic testing for personalized medicine tailored to population characteristics.