We found one instance of a mutation in an affected patient that was absent in both unaffected parents (i.e., a new germ-line mutation), indicating that some "isolate" cases of retinitis pigmentosa carry a mutation of the rhodopsin gene.
This mutation, detected in leukocyte DNA, corresponds to a substitution of leucine for proline in amino acid 347 of the rhodopsin protein, and, therefore, we designated this form of retinitis pigmentosa as rhodopsin, proline-347-leucine.
An important step in the understanding of RP has been the recognition that some cases of autosomal dominant RP (ADRP) are caused by mutations in the rhodopsin gene.
We now present a linkage analysis between D3S47 and the rhodopsin locus (RHO) in five proven rhodopsin-retinitis pigmentosa (rhodopsin-RP) families, using the causative mutations as highly informative polymorphic markers.
Using a model based upon primate data of rod outer segment length and turnover, we have calculated that the delayed phase of the recovery of rod sensitivity in the RP patients tested following strong light adaptation could be due in part to formation of new disc membrane with its normal concentration of rhodopsin rather than in situ regeneration of photopigment.
We inserted into the germline of mice either a mutant or wild-type allele from a patient with retinitis pigmentosa and a missense mutation (P23H) in the rhodopsin gene.
PDE beta is the second member of the phototransduction cascade besides rhodopsin that is absent or altered as a cause of retinitis pigmentosa, suggesting that other members of this pathway may be defective in other forms of this disease.