RS1 and X-linked retinoschisis: X-linked retinoschisis (XLRS) is a leading cause of inherited juvenile macular degeneration in males.89,90 Affected males show visual impairment and bilateral foveal schisis early in life, generally between infancy and school age, however, the level of visual impairment varies.91,92 The disease is an X-linked disorder that is caused by mutations in the XLRS1 gene.