PDE6B and glomerulonephritis: In four cases (RP-0567, RP-1021, RP-1702, and RP-3047), visual alteration was clearly explained by causal variants in early-onset RD genes, i.e., RPGRIP1 (MIM *605446), PDE6B (MIM *180072), RPGR (MIM *312610), and RDH12. However, other systemic presentations, including myopathic alterations, glomerulonephritis, preaxial polydactyly, genital abnormalities, and dysmorphic features, remained unsolved.