CENTRAL ELLIPSOID LOSS ASSOCIATED WITH CONE DYSTROPHY AND KCNV2 MUTATION

Area of Science:

• Ophthalmology
• Genetics
• Retinal Diseases

Background:

• Cone dystrophy with supernormal rod electroretinogram (CSNRE) is a rare monogenic disorder.
• Mutations in the KCNV2 gene are implicated, affecting potassium channels in photoreceptors.

Observation:

• A 38-year-old male presented with vision loss and photophobia.
• Spectral domain optical coherence tomography revealed central ellipsoid zone atrophy.
• Fundus autofluorescence showed mild perifoveal mottling.

Findings:

• Electroretinography demonstrated diminished rod responses with delayed timing but normal maximal rod response.
• Cone responses showed selective b-wave loss with a normal a-wave, characteristic of cone dystrophy.
• Genetic analysis identified a frameshift mutation in the KCNV2 gene.

Implications:

• This case illustrates the multimodal retinal findings and signature electroretinogram in KCNV2-associated CSNRE.
• Ophthalmologists should consider this rare condition in patients with central ellipsoid loss and cone dystrophy.
• Understanding KCNV2 mutations advances knowledge of photoreceptor function and genetic retinal diseases.