A Rare Case of Atypical Mild Enhanced S-Cone Syndrome Associated With Foveoschisis

Abstract

Purpose: To report an atypical presentation of enhanced S-cone syndrome associated with bilateral foveoschisis and an almost normal fundus appearance. Methods: A single case was reviewed. Results: Enhanced S-cone syndrome is a rare inherited retinal dystrophy caused by mutations in the NR2E3 gene, which plays a critical role in the differentiation of photoreceptor cells. Although characteristic findings include nummular pigmentary alterations around the vascular arcades, our patient presented with unilateral visual impairment and bilateral foveoschisis detected on multimodal imaging despite an almost normal fundus appearance. Genetic analysis revealed a homozygous mutation in the NR2E3 gene. The genetic findings and the electrophysiological test results led to a diagnosis of an atypical form of enhanced S-cone syndrome associated with foveoschisis. Conclusions: This case highlights the phenotypic variability of enhanced S-cone syndrome and that electrophysiologic evaluation and genetic analysis play a crucial role in understanding genotype–phenotype correlations, which are essential for guiding prognosis and treatment strategies.