CHOROIDEREMIA ASSOCIATED WITH A NOVEL SYNONYMOUS MUTATION IN GENE ENCODING REP-1.

Area of Science:

• Ophthalmology
• Genetics
• Molecular Biology

Background:

• Choroideremia (CHM) is an X-linked inherited retinal dystrophy.
• Caused by mutations in the CHM gene, it leads to progressive vision loss.
• Synonymous mutations are rarely identified as disease-causing variants.

Observation:

• A 34-year-old man presented with progressive night blindness and visual field constriction.
• Ocular examination and multimodal imaging revealed extensive chorioretinal degeneration.
• CHM gene sequencing identified a hemizygous c.1359C>T, p.(S453S) variant.

Findings:

• The identified c.1359C>T, p.(S453S) variant in the CHM gene is a novel synonymous mutation.
• This variant was found to be hemizygous in the affected male patient.
• The patient's mother was heterozygous for the variant and displayed a classic CHM carrier phenotype.

Implications:

• This study identifies the first synonymous mutation in CHM associated with choroideremia.
• The findings expand the spectrum of CHM-causing mutations.
• Highlights the importance of considering synonymous variants in genetic diagnostics for inherited retinal diseases.