X-linked dominant cone-rod degeneration: linkage mapping of a new locus for retinitis pigmentosa (RP 15) to Xp22.13-p22.11

Am J Hum Genet. 1995 Jul;57(1):87-94.


Retinitis pigmentosa is the name given to a heterogeneous group of hereditary retinal degenerations characterized by progressive visual field loss, pigmentary changes of the retina, abnormal electroretinograms, and, frequently, night blindness. In this study, we investigated a family with dominant cone-rod degeneration, a variant form of retinitis pigmentosa. We used microsatellite markers to test for linkage to the disease locus and excluded all mapped autosomal loci. However, a marker from the short arm of the X chromosome, DXS989, showed 0% recombination to the disease locus, with a maximum lod (log-odds) score of 3.3. On the basis of this marker, the odds favoring X-linked dominant versus autosomal dominant inheritance are > 10(5):1. Haplotype analysis using an additional nine microsatellite markers places the disease locus in the Xp22.13-p22.11 region and excludes other X-linked disease loci causing retinal degeneration. The clinical expression of the retinal degeneration is consistent with X-linked dominant inheritance with milder, variable effects of Lyonization affecting expression in females. On the basis of these data we propose that this family has a novel form of dominant, X-linked cone-rod degeneration with the gene symbol "RP15."

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Chromosome Mapping
  • DNA, Satellite / analysis
  • Female
  • Genetic Linkage*
  • Humans
  • Lod Score
  • Middle Aged
  • Pedigree
  • Photoreceptor Cells / chemistry*
  • Photoreceptor Cells / ultrastructure
  • Retinitis Pigmentosa / genetics*
  • X Chromosome*


  • DNA, Satellite