X-linked retinoschisis: report of a family with a rare deletion in the xLRS1 gene

To describe the clinical features and identify the disease causing mutation in a family with X-linked retinoschisis. Cohort study. Genealogical investigation and mutation screening of the XLRS1 gene were performed in a four generation family of Icelandic ancestry. Three affected family members were evaluated clinically over a 29-year period. A rarely reported, four base pair deletion (375– 378 del AGAT) in exon 5 of the XLRS1 gene was found in all affected males. A high degree of intrafamilial variability was observed in the progression of the disorder over 29 years. Identification of the disease causing mutation in this family allows for the diagnosis of individuals at risk for this inherited macular degeneration. Furthermore, the long-term follow-up of subjects with identical mutations helps to better characterize the highly variable clinical course of this disorder.