Purpose: To report a novel synonymous mutation in CHM and the associated phenotype in an affected man and carrier mother.
Methods: Case report.
Results: A 34-year-old man with a long history of progressive night blindness and visual field constriction was diagnosed with choroideremia based on ocular examination and multimodal retinal imaging. Extensive chorioretinal degeneration was noted on spectral domain optical coherence tomography and fundus autofluorescence imaging. Candidate CHM gene sequencing revealed a hemizygous c.1359C>T, p.(S453S) variant. This variant was heterozygous in the mother of the proband who exhibited the classic carrier phenotype of choroideremia on fundus autofluorescence imaging.
Conclusion: A novel c.1359C>T, p.(S453S) variant in CHM is the first-identified synonymous mutation associated with disease manifestation in an affected man and carrier phenotype in a heterozygous mother.