Juvenile X-linked retinoschisis from XLRS1 Arg213Trp mutation with preservation of the electroretinogram scotopic b-wave

Am J Ophthalmol. 1999 Aug;128(2):179-84. doi: 10.1016/s0002-9394(99)00144-0.


Purpose: To present an Arg213Trp missense mutation in the XLRS1 gene in a family with juvenile X-linked retinoschisis in which one affected male had a normal electroretinogram scotopic b-wave amplitude.

Methods: Two affected males and one unaffected male from this family with X-linked retinoschisis underwent standard clinical examination including an electroretinogram. Mutations in the XLRS1 gene were detected by sequence analysis and by restriction enzyme assay for loss of an MSP-I restriction site.

Results: A missense mutation of C to T at nucleotide position 637 was identified in exon 6 of the XLRS1 gene. This changed the positively charged arginine to a nonpolar tryptophan (Arg213Trp) within the biologically important discoidin domain. Clinical examination revealed intraretinal cysts in a spoke-wheel distribution and early macular atrophy of the retinal pigment epithelium. Whereas the older affected patient had an "electronegative" electroretinogram typical of retinoschisis, the 13-year-old grandson with the same XLRS1 mutation had a normal electroretinogram scotopic b-wave.

Conclusion: Although the electroretinogram is a key diagnostic test for X-linked retinoschisis, this report of a normal electroretinogram scotopic b-wave in a male with molecularly confirmed X-linked retinoschisis indicates that caution is advised in relying on the electroretinogram in differential diagnosis of this condition.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Arginine / genetics
  • DNA / analysis
  • Diagnosis, Differential
  • Electroretinography
  • Exons
  • Eye Diseases, Hereditary / diagnosis
  • Eye Diseases, Hereditary / genetics*
  • Eye Diseases, Hereditary / physiopathology
  • Eye Proteins / genetics*
  • Genetic Linkage*
  • Humans
  • Male
  • Middle Aged
  • Mutation, Missense*
  • Pedigree
  • Polymerase Chain Reaction
  • Retina / physiology*
  • Retinal Degeneration / diagnosis
  • Retinal Degeneration / genetics*
  • Retinal Degeneration / physiopathology
  • Tryptophan / genetics
  • X Chromosome / genetics*


  • Eye Proteins
  • RS1 protein, human
  • Tryptophan
  • DNA
  • Arginine