Abstract
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.
Original language | English (US) |
---|---|
Pages (from-to) | 179-184 |
Number of pages | 6 |
Journal | American Journal of Ophthalmology |
Volume | 128 |
Issue number | 2 |
DOIs | |
State | Published - Aug 1999 |
Externally published | Yes |
ASJC Scopus subject areas
- Ophthalmology