Abstract
Purpose: :
Canine multifocal retinopathy (CMR) is an autosomal recessive disorder characterized by focal RPE and retinal abnormalities. The disease occurs in several dog breeds, including the Great Pyrenees and the Coton de Tulear. Based on phenotypic similarities observed in RPE and retinal lesions among humans and dogs, we propose CMR as a relevant animal model for human retinopathies. The present study was undertaken to evaluate potential candidate genes for CMR with the aim of identifying the underlying gene and causative mutation(s).
Methods: :
Four candidate genes (ABCA4, PRPH2, VMD2 and ELOVL4), related to the human RPE/retinal pathologies have been identified, and examined. Depending on gene size, we have used either haplotype analysis or exon scanning and sequencing, in selected pedigrees of Coton de Tulear and Great Pyrenees in which CMR segregated as an autosomal recessive disorder.
Results: :
The ATP–binding cassette transporter gene, ABCA4, was examined using haplotype analysis with selected intragenic SNPs. Heterozygosity in affected animals was found, thus excluding this gene from causal association with CMR in the Coton de Tulear and Great Pyrenees. The evaluation of remaining candidate genes using exon screening is in progress.
Conclusions: :
Identification of the CMR causal mutation(s) will serve a relevant animal model for human retinopathy leading to a better understanding the molecular mechanisms of the disease.
Keywords: candidate gene analysis • retinal pigment epithelium • gene screening