A range of clinical phenotypes associated with mutations in CRX, a photoreceptor transcription-factor gene

Mutations in the retinal-expressed gene CRX (cone-rod homeobox gene) have been associated with dominant cone-rod dystrophy and with de novo Leber congenital amaurosis. However, CRX is a transcription factor for several retinal genes, including the opsins and the gene for interphotoreceptor retinoid binding protein. Because loss of CRX function could alter the expression of a number of other retinal proteins, we screened for mutations in the CRX gene in probands with a range of degenerative retinal diseases. Of the 294 unrelated individuals screened, we identified four CRX mutations in families with clinical diagnoses of autosomal dominant cone-rod dystrophy, late-onset dominant retinitis pigmentosa, or dominant congenital Leber amaurosis (early-onset retinitis pigmentosa), and we identified four additional benign sequence variants. These findings imply that CRX mutations may be associated with a wide range of clinical phenotypes, including congenital retinal dystrophy (Leber) and progressive diseases such as cone-rod dystrophy or retinitis pigmentosa, with a wide range of onset.