Abstract
BACKGROUND: Mutations in the EYS (eyes shut homolog) gene are a known cause of autosomal recessive retinitis pigmentosa (arRP). Pathogenic variants in EYS have been associated with a more severe clinical course compared to mutations in other retinitis pigmentosa (RP)-related genes. The prevalence of EYS-related arRP varies among different populations. To date, no studies have described the presence of EYS mutations in Puerto Rican patients. This case series aims to report and characterize EYS mutations in RP patients from Puerto Rico. METHODS: This retrospective case series was conducted at two major ophthalmology clinics in Puerto Rico from 2019 to 2023. A chart review was performed to identify RP patients who had mutations in the EYS gene, identified through the Invitae Inherited Retinal Disease Panel, which evaluates more than 300 genes. Collected data included demographic information (age and gender), ocular and medical history, clinical presentation of RP, best corrected visual acuity (BCVA), and genetic testing results. RESULTS: Seven Puerto Rican patients, three females (43%) and four males (57%), with a clinical diagnosis of RP, were found to have pathogenic EYS variants. Among them, four patients (57%) carried the c.5928-2A>G variant, two (29%) had c.6794del, one (14%) had c.1211dup, and one (14%) had c.3443+1G>T. Compound heterozygosity in the EYS gene was observed in two patients. Additionally, three variants of unknown significance (VUS) were identified. Patients exhibited a wide range of visual acuity; however, those older than 40 were found to be legally blind. Conclusions: This study provides evidence of EYS-related RP in Puerto Rican patients. Four truncating mutations in the EYS gene were identified, with c.5928-2A>G being the most frequent. Additionally, the novel EYS variant c.9263G>A (p.Gly3088Glu), classified as VUS, was identified in one patient.