A new locus for autosomal dominant retinitis pigmentosa on chromosome 7p

Autosomal dominant retinitis pigmentosa (adRP) is known to result from mutations in two different retinal genes—rhodopsin and peripherin—while a third locus has been implicated by linkage data. However, families have been reported in which all three known loci have been excluded. We report linkage of adRP in one such family to two microsatellite markers on chromosome 7p. D7S435 has previously been localized to 7p13–15.1; D7S460 , previously only localized to chromosome 7, maps to within 2 cM of D7S435 with a lod score of 12.15. Two point linkage analysis between these markers and adRP gave lod scores of 5.65 (θ = 0) and 4.19 (θ = 0.046) for D7S460 and D7S435 , respectively. Multipoint analysis gave a maximum lod score of 8.22. These data strongly suggest a new adRP locus on chromosome 7p.