Abstract: Objective To summarize and analyze the phenotypic and genotypic characteristics of Chinese carriers with CHM gene variation and compare with foreign carriers. Design Retrospective case series. Participants Six carriers from five choroideremia families with CHM gene variation identifying in the Beijing Tongren Eye Center. Methods The proband and family members underwent detailed ophthalmological examination. Sanger sequencing, target exonm sequencing (TES) and real-time quantitative PCR were used to determine the pathogenic variations of CHM gene in 5 CHM families. Main outcome measures Visual acuity, fundus image, optical coherence tomography image (OCT), fundus autofluorescence (FAF) and gene variations carried by each carrier. Results 6 carriers came from 5 unrelated families. A total of 5 CHM gene variations were detected in these carriers. The average age of all female carriers was（34.00±14.83） years (range 8~53 years old). They had no symptoms, such as decreased vision, night blindness, and visual field contraction. The fundus images showed punctate or flaky hypopigmentation of the retina, which can be accompanied by small yellowish well-defined dots. Mottled flake or mosaic-like low fluorescence could be seen on FAF, with dotted hyperfluorescence. Two carriers were followed up for three years. Their eyesights were stable and their fundus was almost unchanged. Conclusion This study expanded the variation spectrum of CHM gene variations. Compared with European and American carriers with CHM gene variations, the damage of visual function and fundus changes of Chinese female carriers were slighter. (Ophthalmol CHN, 2021, 30: 211-216)

Key words: choroideremia, CHM gene, carrier