X-linked retinoschisis -: Novel mutation in the initiation codon of the XLRS1 gene in a large family

Purpose: To describe a novel point mutation in the initiation codon of the XLRS1 gene in a large family and the clinical features of males affected with X-linked juvenile retinoschisis. Methods: Genealogic investigation and mutation screening of the XLRS1 gene were performed for a 4-generation family consisting of 72 members. Affected males were evaluated clinically between 1986 and 2004 with up to 18 years of follow-up. Results: We identified a novel point mutation (1A>T transversion) in the initiation codon of the XLRS1 gene in affected males resulting in an amino acid substitution of methionine to leucine (Met1 Leu), therefore abolishing the translation initiation Met codon. Conclusion: Identification of the disease-causing mutation in this family with long-term follow-up allows for earlier and more accurate identification of individuals at risk for this inherited progressive macular degeneration, provides for more accurate genetic counseling, and contributes to our understanding of the pathophysiology of this disorder.