NM_001034853.2(RPGR):c.3034del (p.Glu1012LysfsTer?) is a frameshift variant due to a 1-nucleotide deletion introducing a premature stop codon in exon 15 of 15, which is predicted to disrupt a critical C-terminal region required for proper glutamylation of RPGR (PVS1, PMID: 36445968). This variant was confirmed to result in a 40% decrease in glutamylation of RPGR when co-transfected into HEK293 cells with the glutamylase TTLL5 (PMID: 36445968), however, PS3_Supporting was not scored as PVS1 has already been met. This variant is absent from gnomAD v4.1.0 (PM2_Supporting). This variant has been reported in at least 2 apparently unrelated probands (PMIDs: 36445968, 30543658). However, the number of individuals meeting the PS4 requirement of some functional vision impairment in affected males by age 30 years, and/or decreased or absent electroretinogram responses was fewer than the requirement of at least 2 unrelated probands, so PS4_Supporting was not met. In summary, this variant is classified as likely pathogenic for RPGR-related retinopathy based on the ClinGen X-linked Inherited Retinal Disease Expert Panel Specifications to the ACMG/AMP Variant Interpretation Guidelines for RPGR Version 1.0.0; PVS1 and PM2_Supporting.