Mutations in the retinal guanylate cyclase (RETGC-1) gene in dominant cone-rod dystrophy

The dominant cone-rod dystrophy gene CORD6 has previously been mapped towithin an 8 cM interval on chromosome 17p12-p13. The retinal- specificguanylate cyclase gene (RETGC-1), which maps to within this geneticinterval and previously was implicated in Leber's congenital amaurosis, wasscreened for mutations within this family and in a panel of small familiesand individuals with various cone and cone- rod dystrophy phenotypes. Amissense mutation (E837D) was identified in affected members of the CORD6family, as well as a second missense mutation (R838C) in three otherfamilies with dominant cone-rod dystrophy. RETGC-1 is only the fourth geneto be implicated in cone-rod dystrophy and this is the first report ofdominant mutations in this gene.