Abstract: Objective To identify the mutations of the RS1 gene in Chinese patients with X-linked retinoschisis (XLRS) and describe their associated phenotype. Design Retrospective cases series. Participants 27 patients including 12 patients with family history and 15 sporadic cases with retinolschisis were recruited. Methods All the exons including the exon-intron boundaries of the RS1 gene, were amplified by PCR and the products were analyzed by direct sequencing in all the patients, and each proband underwent clinical examinations, including best-corrected visual acuity (BCVA) using E decimal charts, slit-lamp biomicroscopy, fundus examination and photography, optical coherence tomography (OCT)，and electronic retinogram (ERG). Main Outcome Measures Mutations of RS1 gene, onset age, visual acuity, fundus appearances. Results 27 RS1 gene mutations were found in 27 unrelated families, 4 of which were novel and 22 of which were located in exon 4-6 that encodes the discoidin domain of RS1 gene (85.2%). The mutations contained 15 missence mutations (55.6%), 4 nonsense mutations(14.8%), 4 deletions/insertions (14.8%), 2 splice site mutations(7.4%), and 2 large genomic deletions (7.4%). All patients were males, the median age of onset was 4.70±1.25 years (rang 0-34 years), the median BCVA upon review was 0.22±0.289 (rang hand motion-1.0). Of all the 27 patients (54 eyes), 40 eyes had typical macular schisis(74.1%), 7 eyes only had peripheral retinal schisis, 5 eyes had macular atrophy in which 3 had peripheral retinal schisis. Conclusion The mutations found in this study broaden the spectrum of RS1 gene mutations, and the exon 4-6 was the hot region of RS1 gene mutations, so these region should be given priority for RS1 gene mutation screening. (Ophthalmol CHN, 2015, 24: 90-95)

Key words: X-linked retinoschisis, RS1 gene , gene mutations