OPA1 and autosomal dominant optic atrophy: In a retinal organoid model of XLRS from a patient with the c.625C/T (p.Arg209Cys) variant in the RS1 gene, a progressive loss of OPA1 gene expression was observed, with OPA1 mutations being the most common genetic cause of autosomal dominant optic atrophy.2 24 Thus, some RS1 pathogenic variants in patients with XLRS might be associated with decreased OPA1 gene expression, which could explain diffuse RNFL thinning in some patients.