ObjectiveTo report the clinical findings and RS1 gene mutation analysis of a Chinese family with X-linked juvenile retinoschisis (XLRS). MethodsThe pedigree of this XLRS family was studied. Nine individuals (10 eyes of 6 males, 6 eyes of 3 females), including the proband, received ocular examination, fundus photography and optical coherence tomography (OCT). Direct DNA sequencing of the 6 exons of RS1 gene was used to detect the RS1 mutation in 12 family members. ResultsThe present pedigree included 15 members of three generations. Among them, 5 male members were diagnosed with XLRS. The retina of other 4 family members were normal, including 1 male (2 eyes) and 3 females (6 eyes). Visual acuity of these 5 patients ranged from hand movement to 0.5 and both eyes of them were involved. The age when visual acuity begins to decrease was all less than 10 years. Fundus color photographic examination showed macular radial cystoid retinoschisis and retinoschisis of the peripheral retina. OCT images showed retinoschisis in macular regions (8 eyes) or peripheral retina (6 eyes). Genetic testing showed that 1 male had no mutation in RS1 gene (p.Gly109Val). All 5 patients had a point mutation (c.326G>T) at exon 4 of RS1 gene, which cause the 109th amino acid changed from glycine to valine in the RS1 protein. A 3-year-old kid also had this mutation. The 3 females with normal retina had heterozygous mutations of Gly109Val, so they are the mutation carriers. ConclusionThe novel p.Gly109Val mutation is the causing mutation in this Chinese family with X-linked juvenile retinoschisis.
X-linked retinoschisis (XLRS) is a rare X-linked inherited retinal disorder, caused by mutations in retinoschisin 1 (RS1) gene. Three XLRS mice were established, providing ideal systems to study the mechanism and treatment methods for XLRS. RS1 gene mutations can induce abnormal secretion or adhesion function of RS1 protein. In the past year, phase I clinical trials for XLRS has begun in USA, using adeno associated virus (AAV, AAV8 or AAV2)-mediated gene delivery. With the rapid development of new generation of AAV vector that can transduce more retinal cells through intravitreous delivery, gene therapy for XLRS will have a brighter future.