A 25-year-old woman presented to our clinic with decreased vision in the right eye as well as night blindness. The patient was systemically healthy and had no history of ocular trauma or uveitis. She could not easily navigate a dark movie theater without support since high school, but it did not worsen, and the condition was maintained. She reported a family history of RP with poor vision and nyctalopia involving her maternal grandfather and maternal cousin. However, we were unable to ophthalmologically examine for her family members. The family pedigree based on history and symptoms is shown in Fig.. On examination, the best-corrected visual acuity was 20/100 in the right eye (OD) and 20/20 in the left eye (OS). Her refractive error was -4.0 Dsph = -4.0 Dcyl x A180 OD and -1.25 Dsph = -3.25 Dcyl x A20 OS. A slit-lamp examination revealed no specific findings. Fundus examination revealed multiple bone spicule pigmentations and attenuation of retinal vessels in the OD. Tessellated fundus changes within the posterior pole were also observed. However, no conspicuous bone spicule pigmentation was found, with an almost normal appearance of the retina in the OS. Optical coherence tomography (OCT) revealed visible thinning of the entire outer retina and generalized disruption of foveal microstructures, with a small area of preserved faint ellipsoid zone subfoveally in the OD. Localized attenuation and losses in the ellipsoid zone band were observed in OS. Fundus autofluorescence (FAF) revealed multiple patchy and reticular hypoautofluorescent lesions with abnormal hyperautofluorescence in the fovea of the OD. Interestingly, a completely different aspect of the FAF findings was noted in the OS: a tapetal-like reflex showing a characteristic bright radial reflex against a dark background. Ultra-widefield fluorescein angiography (FA) imaging showed diffuse, blotchy, or mottled hyperfluorescence corresponding to the affected whole retinal areas in the OD. No specific abnormalities were identified in the OS. Optical coherence tomography angiography (OCTA) revealed significantly reduced retinal vessel density, blood flow, and retinal thinning in the OD. Goldmann perimetry demonstrated a central visual field within 10° and islands of the visual field, particularly on the inferior side of the OD. A central scotoma was also identified in the remaining central visual field. A normal visual field with a physiological blind spot was observed in the OS. Electrophysiologic assessment was performed, and electroretinography (ERG) revealed an extinguished rod response and a severely impaired cone response in the OD. The amplitudes of the rod and cone responses were unremarkable in the OS, revealing marked asymmetry in both the structure and function of the retina. Molecular genetic tests using next-generation sequencing (NGS)-based gene panels were performed using peripheral blood samples obtained from patient after providing informed consent. The exome-based targeted panel comprised 244 candidate genes associated with inherited retinal diseases and screened the coding region and its flanking region of the gene using the NovaSeq system (Illumina, USA) (). The variant interpretation was performed using the guidelines of the American College of Medical Genetics and Genomics (ACMG) []. We identified a novel RP2 mutation (c.803dup) in exon 3 at position 803 that caused a frameshift and premature termination signal at codon 269 (RP2, p.Glu269Glyfs*7, heterozygote). These changes have not been previously reported in the literature. This corresponded to the carrier of XLRP2, and no other pathogenic or likely pathogenic variants were identified among the 244 inherited retinal disease-related genes. The possibility of pathological mutations not being assessed cannot be excluded.