Retinoschisin 1 (RS1) is an X-linked gene encoding a retinal protein essential for normal retinal structure and function 1. RS1 protein binds negatively charged membrane lipids, including phosphatidylserine and phosphoinositides, and mediates cell-cell adhesion through homomeric octamer interactions between neighboring retinal cells 2. The protein is predominantly expressed in photoreceptors and inner nuclear layer bipolar neurons, where it maintains retinal architectural integrity 3. RS1 mutations cause X-linked juvenile retinoschisis (XLRS), an early-onset inherited retinal dystrophy characterized by transretinal splitting and visual impairment beginning in early childhood 4. The condition affects males exclusively with complete penetrance, while carrier females typically remain asymptomatic, with estimated prevalence of 1 in 5,000-25,000 men 4. Pathogenic variants impair protein folding and trafficking, causing intracellular retention within the endoplasmic reticulum rather than proper extracellular localization 5. This disrupts synaptic signal transmission from photoreceptors to ON-bipolar cells, disproportionately reducing the electroretinogram bipolar b-wave 3. Gene augmentation therapy using AAV8-mediated RS1 delivery shows promise, rescuing photoreceptor developmental delays in patient-derived organoids and restoring retinal structure and synaptic function in animal models 63. Clinical trials demonstrate therapeutic potential, particularly when intervention occurs before irreversible retinal degeneration 37.