Clinical features of X linked juvenile retinoschisis in Chinese families associated with novel mutations in the RS1 gene

PURPOSE To describe the clinical phenotype of X linked juvenile retinoschisis (XLRS) in 12 Chinese families with 11 different mutations in the XLRS1 (RS1) gene. METHODS Complete ophthalmic examinations were carried out in 29 affected males (12 probands), 38 heterozygous females carriers, and 100 controls. The coding regions of the RS1 gene that encodes retinoschisin were amplified by polymerase chain reaction and directly sequenced. RESULTS Of the 29 male participants, 28 (96.6%) displayed typical foveal schisis. Eleven different RS1 mutations were identified in 12 families; four of these mutations, two frameshift mutations (26 del T of exon 1 and 488 del G of exon 5), and two missense mutations (Asp145His and Arg156Gly) of exon 5, had not been previously described. One non-disease-related polymorphism (NSP): 576C to T (Pro192Pro) change was also newly reported herein. We compared genotypes and observed more severe clinical features in families with the following mutations: frameshift mutation (26 del T) of exon 1, the splice donor site mutation (IVS1+2T to C),or Arg102Gln, Arg209His, and Arg213Gln mutations. CONCLUSIONS Severe XLRS phenotypes are associated with the frameshift mutation 26 del T, splice donor site mutation (IVS1+2T to C), and Arg102Gln, Asp145His, Arg209His, and Arg213Gln mutations. The wide variability in the phenotype in Chinese patients with XLRS and different mutations in the RS1 gene is described. Identification of mutations in the RS1 gene and expanded information on clinical manifestations will facilitate early diagnosis, appropriate early therapy, and genetic counseling regarding the prognosis of XLRS.