JAPANESE JUVENILE RETINOSCHISIS IS CAUSED BY MUTATIONS OF THE XLRS1 GENE

We investigated the XLRS1 gene in Japanese patients with retinoschisis (RS). All exons of the XLRS1 gene were sequenced in 14 males, includi ng a pair of monozygotic twins, from 11 individual families with RS an d five of their mothers who are asymptomatic but diagnosed as carriers . Six kinds of missense mutations and a nonsense mutation, including s ix novel mutations, were detected in all 14 patients and carriers. Mut ations in the XLRS1 gene are also responsible for RS in non-Caucasian patients. Most Japanese RS cases are caused by an XLRS1 gene defect. A novel mutation, Glu72Lys. was found in four families, suggesting a co mmon mutation in the Japanese population. Clinical features of RS pati ents with both the Glu72Lys and Pro193Leu mutations indicate that a ge notype-phenotype correlation is not recognized in RS.