The Gene Diagnosis And Analysis Of Two X-linked Juvenile Retinoschisis Families

X-linked juvenile retinoschisis(XLRS) is a rare heritage ophthalmocace, the disease rate is about 1/5000～1/25000. XLRS mainly affects bilateral retina, and the retina appear schisis or splitting within the inner retinal layers. This disease is characterized by cartwheel-like changes of the macular region. This disease only affects males and carrier females remain asymptomatic. XLRS is the first cause of juvenile macula lutea denaturation. There is still no effective therapy of XLRS. The final result of the patient is to be blind. The responsible gene, XLRS1, maps to Xp22 and was recently identified by positional cloning. It consists of six exons and encodes the protein retinoschisin, a 224 amino acid protein which contains a highly conserved discoidin domain, encoded by exons 4 to 6. The function of this protein has not been identified. Some scholars think this protein is thought to play an important role in cell adhesion, cell-cell interaction or phospholipid binding on membrane surfaces that maintains the integrity of the retina. It has been verified that XLRS is caused by mutation of XLRS1 and now 151 different mutations in this gene have been reported (www.dmd.nl/rs.html), including 98 missense/nonsense mutations, 31 deletion mutations, 7 insertion mutations, 13 splicing mutations.ObjectiveThrough diagnosising and analysising the gene mutations of two X-linked juvenile retinoschisis families, to provid foundation and thinking to study pathogenesy and explore effective therapy of XLRS.Materials and Methods1.materials: 52 samples from 2 XLRS families, including 6 XLRS patients. 30 collators without disease and blood relationship with samples.2.methods: To screen the XLRS1 gene mutation in 2 families by using PCR-SSCP, and to confirm mutation type by using DNA sequencing.ResultTwo different missense mutations were identified in 2 families. They conclude: c.626G>A(p.R209H),c.422G>A(p.R141H). Ten carriers were identified in 2 families.ConclusionsThis two families were caused by mutation of XLRS1. The result can be directly used in prenatal diagnosis for families members. The c.422G> A(p.R141H) has not been previously reported in Chinese. The mutation of XLRS1 gene has not race specificity.