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Am J Hum Genet. Nov 1998; 63(5): 1439–1447.
PMCID: PMC1377555

A novel locus (RP24) for X-linked retinitis pigmentosa maps to Xq26-27.


Two genetic loci, RP2 and RP3, for X-linked retinitis pigmentosa (XLRP) have been localized to Xp11.3-11.23 and Xp21.1, respectively. RP3 appears to account for 70% of XLRP families; however, mutations in the RPGR gene (isolated from the RP3 region) are identified in only 20% of affected families. Close location of XLRP loci at Xp and a lack of unambiguous clinical criteria do not permit assignment of genetic subtype in a majority of XLRP families; nonetheless, in some pedigrees, both RP2 and RP3 could be excluded as the causative locus. We report the mapping of a novel locus, RP24, by haplotype and linkage analysis of a single XLRP pedigree. The RP24 locus was identified at Xq26-27 by genotyping 52 microsatellite markers spanning the entire X chromosome. A maximum LOD score of 4.21 was obtained with DXS8106. Haplotype analysis assigned RP24 within a 23-cM region between the DXS8094 (proximal) and DXS8043 (distal) markers. Other chromosomal regions and known XLRP loci were excluded by obligate recombination events between markers in those regions and the disease locus. Hemizygotes from the RP24 family have early onset of rod photoreceptor dysfunction; cone receptor function is normal at first, but there is progressive loss. Patients at advanced stages show little or no detectable rod or cone function and have clinical hallmarks of typical RP. Mapping of the RP24 locus expands our understanding of the genetic heterogeneity in XLRP and will assist in development of better tools for diagnosis.

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Selected References

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  • Aldred MA, Teague PW, Jay M, Bundey S, Redmond RM, Jay B, Bird AC, Bhattacharya SS, Wright AF. Retinitis pigmentosa families showing apparent X linked inheritance but unlinked to the RP2 or RP3 loci. J Med Genet. 1994 Nov;31(11):848–852. [PMC free article] [PubMed]
  • Becker A, Geiger D, Schäffer AA. Automatic selection of loop breakers for genetic linkage analysis. Hum Hered. 1998 Jan-Feb;48(1):49–60. [PubMed]
  • Bergen AA, Pinckers AJ. Localization of a novel X-linked progressive cone dystrophy gene to Xq27: evidence for genetic heterogeneity. Am J Hum Genet. 1997 Jun;60(6):1468–1473. [PMC free article] [PubMed]
  • Berson EL, Rosen JB, Simonoff EA. Electroretinographic testing as an aid in detection of carriers of X-chromosome-linked retinitis pigmentosa. Am J Ophthalmol. 1979 Apr;87(4):460–468. [PubMed]
  • Bhattacharya SS, Wright AF, Clayton JF, Price WH, Phillips CI, McKeown CM, Jay M, Bird AC, Pearson PL, Southern EM, et al. Close genetic linkage between X-linked retinitis pigmentosa and a restriction fragment length polymorphism identified by recombinant DNA probe L1.28. Nature. 1984 May 17;309(5965):253–255. [PubMed]
  • Birch DG, Fish GE. Rod ERGs in retinitis pigmentosa and cone-rod degeneration. Invest Ophthalmol Vis Sci. 1987 Jan;28(1):140–150. [PubMed]
  • Buraczynska M, Wu W, Fujita R, Buraczynska K, Phelps E, Andréasson S, Bennett J, Birch DG, Fishman GA, Hoffman DR, et al. Spectrum of mutations in the RPGR gene that are identified in 20% of families with X-linked retinitis pigmentosa. Am J Hum Genet. 1997 Dec;61(6):1287–1292. [PMC free article] [PubMed]
  • Chen YT, Rettig WJ, Yenamandra AK, Kozak CA, Chaganti RS, Posner JB, Old LJ. Cerebellar degeneration-related antigen: a highly conserved neuroectodermal marker mapped to chromosomes X in human and mouse. Proc Natl Acad Sci U S A. 1990 Apr;87(8):3077–3081. [PMC free article] [PubMed]
  • Cideciyan AV, Hood DC, Huang Y, Banin E, Li ZY, Stone EM, Milam AH, Jacobson SG. Disease sequence from mutant rhodopsin allele to rod and cone photoreceptor degeneration in man. Proc Natl Acad Sci U S A. 1998 Jun 9;95(12):7103–7108. [PMC free article] [PubMed]
  • Cideciyan AV, Jacobson SG. Negative electroretinograms in retinitis pigmentosa. Invest Ophthalmol Vis Sci. 1993 Nov;34(12):3253–3263. [PubMed]
  • Fishman GA, Weinberg AB, McMahon TT. X-linked recessive retinitis pigmentosa. Clinical characteristics of carriers. Arch Ophthalmol. 1986 Sep;104(9):1329–1335. [PubMed]
  • Fujita R, Buraczynska M, Gieser L, Wu W, Forsythe P, Abrahamson M, Jacobson SG, Sieving PA, Andréasson S, Swaroop A. Analysis of the RPGR gene in 11 pedigrees with the retinitis pigmentosa type 3 genotype: paucity of mutations in the coding region but splice defects in two families. Am J Hum Genet. 1997 Sep;61(3):571–580. [PMC free article] [PubMed]
  • Jacobson SG, Buraczynska M, Milam AH, Chen C, Järvaläinen M, Fujita R, Wu W, Huang Y, Cideciyan AV, Swaroop A. Disease expression in X-linked retinitis pigmentosa caused by a putative null mutation in the RPGR gene. Invest Ophthalmol Vis Sci. 1997 Sep;38(10):1983–1997. [PubMed]
  • Jacobson SG, Yagasaki K, Feuer WJ, Román AJ. Interocular asymmetry of visual function in heterozygotes of X-linked retinitis pigmentosa. Exp Eye Res. 1989 May;48(5):679–691. [PubMed]
  • Lathrop GM, Lalouel JM, Julier C, Ott J. Strategies for multilocus linkage analysis in humans. Proc Natl Acad Sci U S A. 1984 Jun;81(11):3443–3446. [PMC free article] [PubMed]
  • Li ZY, Wong F, Chang JH, Possin DE, Hao Y, Petters RM, Milam AH. Rhodopsin transgenic pigs as a model for human retinitis pigmentosa. Invest Ophthalmol Vis Sci. 1998 Apr;39(5):808–819. [PubMed]
  • McGuire RE, Sullivan LS, Blanton SH, Church MW, Heckenlively JR, Daiger SP. 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. [PMC free article] [PubMed]
  • Meindl A, Dry K, Herrmann K, Manson F, Ciccodicola A, Edgar A, Carvalho MR, Achatz H, Hellebrand H, Lennon A, et al. A gene (RPGR) with homology to the RCC1 guanine nucleotide exchange factor is mutated in X-linked retinitis pigmentosa (RP3). Nat Genet. 1996 May;13(1):35–42. [PubMed]
  • Musarella MA, Anson-Cartwright L, Leal SM, Gilbert LD, Worton RG, Fishman GA, Ott J. Multipoint linkage analysis and heterogeneity testing in 20 X-linked retinitis pigmentosa families. Genomics. 1990 Oct;8(2):286–296. [PubMed]
  • Ott J, Bhattacharya S, Chen JD, Denton MJ, Donald J, Dubay C, Farrar GJ, Fishman GA, Frey D, Gal A, et al. Localizing multiple X chromosome-linked retinitis pigmentosa loci using multilocus homogeneity tests. Proc Natl Acad Sci U S A. 1990 Jan;87(2):701–704. [PMC free article] [PubMed]
  • Roepman R, van Duijnhoven G, Rosenberg T, Pinckers AJ, Bleeker-Wagemakers LM, Bergen AA, Post J, Beck A, Reinhardt R, Ropers HH, et al. Positional cloning of the gene for X-linked retinitis pigmentosa 3: homology with the guanine-nucleotide-exchange factor RCC1. Hum Mol Genet. 1996 Jul;5(7):1035–1041. [PubMed]
  • Roof DJ, Adamian M, Hayes A. Rhodopsin accumulation at abnormal sites in retinas of mice with a human P23H rhodopsin transgene. Invest Ophthalmol Vis Sci. 1994 Nov;35(12):4049–4062. [PubMed]
  • Schwahn U, Lenzner S, Dong J, Feil S, Hinzmann B, van Duijnhoven G, Kirschner R, Hemberger M, Bergen AA, Rosenberg T, et al. Positional cloning of the gene for X-linked retinitis pigmentosa 2. Nat Genet. 1998 Aug;19(4):327–332. [PubMed]
  • Teague PW, Aldred MA, Jay M, Dempster M, Harrison C, Carothers AD, Hardwick LJ, Evans HJ, Strain L, Brock DJ, et al. Heterogeneity analysis in 40 X-linked retinitis pigmentosa families. Am J Hum Genet. 1994 Jul;55(1):105–111. [PMC free article] [PubMed]
  • Thiselton DL, Hampson RM, Nayudu M, Van Maldergem L, Wolf ML, Saha BK, Bhattacharya SS, Hardcastle AJ. Mapping the RP2 locus for X-linked retinitis pigmentosa on proximal Xp: a genetically defined 5-cM critical region and exclusion of candidate genes by physical mapping. Genome Res. 1996 Nov;6(11):1093–1102. [PubMed]

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