The number of individuals tested for ORF15 seemed to reduce after the introduction of whole genome sequencing (2019).<h4>Conclusions</h4>We identified an estimated 977 living patients with <i>RPGR</i>-associated XLRP from 2594 tested individuals, representing a large absolute number and significant population who could benefit from emerging gene therapy, with prevalence higher than other treatable inherited retinal dystrophies. This evidence concerns the gene RPGR and inherited retinal dystrophy.