Novel 615delC mutation in the CRX gene in a Japanee family with cone-rod dytrophy

Purpoe To characterize the clinical feature of a Japanee family with cone-rod dytrophy aociated with a novel 615delC mutation in the cone-rod homeobox (CRX) gene. Deign Cae report and reult of DNA analyi. Method Mutational creening by direct equencing wa performed for the three exon in the CRX gene. The clinical feature were evaluated by viual acuity meaurement, electroretinography, and kinetic viual field teting. Reult A 615delC mutation in the CRX gene wa identified and found to coegregate with cone-rod dytrophy. The ophthalmic finding included cone-rod dytrophy with negative-type electroretinogram (ERG) and a rapid progreion after the age of 40 year. Concluion Thee finding indicate that the 615delC mutation caue cone-rod dytrophy with a negative-type ERG. The genotype–phenotype correlation in the CRX gene in our patient and other reported in the literature ugget that the negative-type ERG might be a good ign for having a mutation in the CRX gene.