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Background Female carriers of X-linked conditions display a spectrum of disease, often attributed to skewed X-inactivation during embryogenesis. Herein, we describe the phenotype in a female carrier of c.3308_3309delAT (p.Tyr1103Serfs*7) – a frameshift variant in the basic domain of RPGR, which is associated with X-linked cone dystrophy in hemizygous males.Methods Retrospective review of ophthalmic examination results, multimodal retinal imaging and functional testing was conducted.Results A 71-year-old female was examined due to a diagnosis of RPGR-related cone dystrophy in her son. Visual acuities were clinically normal at 6/6, and refractive error measured -6.50/-2.00x15 and -6.00/-1.50x130 in the right and left eye, respectively. Slit-lamp examination was unremarkable. Retinal imaging showed mild foveal hyper-reflectance with green reflectance (518nm) which colocalised with a hyperreflective outer retinal band observed on SD-OCT. Fundus autofluorescence and ultra-widefield imaging showed no peripheral abnormalities. Cone-mediated mesopic microperimetry revealed a mosaic pattern of reduced macular sensitivity despite normal retinal structure on clinical imaging. Handheld electroretinography measured normal rod responses, while cone responses averaged 71.4% of the lower normal limit, compared to 36% in the male proband. This finding corroborates the stochastic nature of X-inactivation.Conclusion This case identifies a phenotype consistent with mild cone dysfunction and anatomical changes. Improved understanding of disease manifestations in female carriers is essential to identify affected individuals who may benefit from future gene-targeted therapies.