Objective: To elucidate the pathogeny of X-linked retinoschisis(XLRS) and evaluate its value in direct gene diagnosis.
Methods: Polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP) assay was performed to examine exons of XLRS1 gene in six unrelated retinoschisis cases (3 families and 3 sporadic cases), and fragments with a mobility shift were sequenced to identify the mutation. The deletion mutations were further identified by Southern blotting analysis.
Results: Three deletions that eliminate exon 1, exon 2, and exon 3 were found in 4 patients of one family. There was severe effect of the mutation in the coding region. Three kinds of mutations were found in exon 4: Glu72Lys, Glu72Gln, Gly70Ser.
Conclusion: XLRS is caused by mutation of the XLRS1 gene. The finding helps establish a fast and effective direct diagnosis.