Clinical Manifestations Associated with EYS Gene Mutations in Iranian Patients with Retinitis Pigmentosa
Bahareh Safdari1 , Hamideh Sabbaghi2 , Zahra Khorrami2 , Shermin Lak1 , Leila Javanparast Sheykhani1 , Hamid Ahmadieh1 , Fatemeh Suri1 *
- Ophthalmic Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Ophthalmic Epidemiology Research Center, Research Institute for Ophthalmology and Vision Science, Shahid Beheshti University of Medical Sciences.
Abstract: The eyes shut homolog (EYS) gene, is the largest eye-specific gene identified to date that plays an essential role in the autosomal recessive retinitis pigmentosa (arRP). To date, several studies have investigated the clinical and genetic characteristics of patients with EYS mutations. However, there is not such data for Iranian patients. This study aimed to investigate the genotype-phenotype correlations in EYS-associated RP patients extracted from recorded data in the national inherited retinal diseases registry of Iran.
Methods: This is a retrospective cross-sectional study on 19 patients with EYS-associated RP recruited out of about 300 registered families with genetical diagnosis by whole exome sequencing (WES). Genotypic classification based on the position and impact of the mutations was done with two different strategies: The first one: Group A;( all variants located in the N-terminus). Group B; (variants located in the both N-terminus and C-terminus), Group C; (all variants located in the C-terminus). Second: Group A; (with 2 severe/null variants), Group B; (with 1 severe/null variant and 1 missense or in-frame insertion/deletion variant); and Group C; (with no severe/ null variant but 2 missense or in-frame insertion/ deletion variants).
Results: In this study, nineteen patients with a mean age of disease onset of 22.35±9.15 were included. The mean of best-corrected visual acuity (BCVA) was 0.9±0.94. 94% of patients had restricted visual field and 73.3% had color vision deficiency. Based on the genotype location classification, most patients belonged to category A in both groups (68.5% and 84%, respectively). The mean of BCVA in category A in groups 1 and 2 were 1.02±1.08 and 0.78±0.91, respectively. Also, 61.5% and 68.7% of patients in category A had color vision deficiency in group 1 and 2, respectively.
Conclusion: This study showed that all the patients in category A, had lower visual acuity and color vision deficiency compared with two other groups. Other research with more sample size and patient follow-up is recommended.
