RPGR and Leber hereditary optic neuropathy: In the pediatric cohort, 78.8% of families showed causative variants in autosomal genes (most frequently ABCA4 and BEST1), 20.7% in X-linked genes (most commonly RS1 and RPGR), and 0.5% in mitochondrial genes (associated with Leber hereditary optic neuropathy).