Phenotypes in three Swedish families with X-linked retinitis pigmentosa caused by different mutations in the RPGR gene

Am J Ophthalmol. 1997 Jul;124(1):95-102. doi: 10.1016/s0002-9394(14)71649-6.

Abstract

Purpose: To assess the clinical phenotypes in three Swedish families with X-linked retinitis pigmentosa caused by different mutations in the RPGR gene.

Methods: Three families from different parts of Sweden, including nine patients with retinitis pigmentosa and six female carriers of X-linked retinitis pigmentosa, were examined clinically. Ophthalmologic examination included kinetic perimetry with a Goldmann perimeter using standardized objects I4e and V4e, dark adaptation final thresholds with a Goldmann-Weeker adaptometer, and full-field electroretinograms.

Results: The clinical findings in the patients demonstrated a severe form of retinitis pigmentosa with visual handicap early in life. Patients with a microdeletion of exons 8 through 10 of the RPGR gene had a more severe phenotype compared to the patients with single base-pair mutations in the introns 10 and 13 of the RPGR gene, resulting in splicing defects. Furthermore, heterozygous carriers in these families displayed a wide spectrum of clinical features, from minor symptoms to severe visual disability.

Conclusion: These three families show a variable clinical phenotype resulting from different mutations in the RPGR gene. A microdeletion spanning at least parts of exons 8 through 10 seems to result in a severe phenotype compared to the splice defects. Heterozygous carriers of X-linked retinitis pigmentosa with these specific RPGR genotypes also show a variability of the phenotype; carriers with the microdeletion may be severely visually handicapped.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Carrier Proteins / genetics*
  • Child
  • Chromosome Deletion
  • Electroretinography
  • Eye Proteins*
  • Female
  • Genetic Linkage*
  • Humans
  • Male
  • Middle Aged
  • Mutation*
  • Pedigree
  • Phenotype
  • Retinitis Pigmentosa / genetics*
  • Retinitis Pigmentosa / physiopathology
  • Retinitis Pigmentosa / rehabilitation
  • Sweden
  • Visual Acuity
  • Visual Fields
  • X Chromosome / genetics*

Substances

  • Carrier Proteins
  • Eye Proteins
  • RPGR protein, human