Cone-rod Dystrophy

Gene: KCNV2

Green List (high evidence)

Additional cases: Seven cases are identified with homozygous variants in KCNV2 gene and reported with cone dystrophy with supernormal rod responses (CDSRR) in PMID:23221069. Similarly, 15 unrelated patients were identified with three different homozygous KCNV2 variants and reported with CDSRR in PMID:31960170. PMID:34535971 reports a Chinese family with compound heterozygous variants and implicated in CDSRR.

Functional studies: KCNV2 knockout mouse exhibits aberrant retinal activities that phenocopies CDSRR patients (PMID:34652420).

Created: 9 Feb 2023, 2:03 p.m. | Last Modified: 9 Feb 2023, 2:14 p.m.

Panel Version: 0.48

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Publications

• 23221069
• 31960170
• 34535971
• 34652420

Green List (high evidence)

Cone dystrophy with supernormal rod responses (CDSRR) is characterized by onset in the first or second decade of life of very marked photophobia, myopia, reduced color vision along the red-green axis with relatively preserved tritan discrimination, and central scotomata with peripheral widespread sensitivity loss predominating in the superior visual field. Nyctalopia is a later feature of the disorder. There is often retinal pigment epithelium disturbance at the macula with a normal retinal periphery. Autofluorescence (AF) imaging shows either a perifoveal ring or a central macular area of relative increased AF.

Well established gene-disease association, more than 10 families reported.

Created: 12 Mar 2022, 1:39 a.m. | Last Modified: 12 Mar 2022, 1:39 a.m.

Panel Version: 0.31

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Retinal cone dystrophy 3B, MIM# 610356

Publications

• 16909397
• 18235024
• 21882291