Three novel mutations in the X-linked juvenile retinoschisis (XLRS1) gene in 6 Japanese patients, 1 of whom had Turner's syndrome.

We examined the XLRS1 gene for mutations in 6 Japanese patients with X-linked juvenile retinoschisis from a total of three families (5 males and 1 female), and from 3 obligate carrier females. DNA was amplified for all six coding exons of the XLRS1 gene with established primer pairs, and was sequenced directly. Each family had a different mutation, Trp96stop, 522+1g-->a, and Lys167Asn in the XLRS1 gene. Affected patients had a hemizygous mutant allele while the obligate carrier females were heterozygotes who had both wild-type and mutant-type alleles. A proband female, who was the offspring of asymptomatic and nonconsanguineous parents, was found to have a chromosomal karyotype (45, X) that was indicative of Turner's syndrome. These three different mutations in the XLRS1 gene have not been previously reported. Further studies are needed to determine the relationship between these defects in the XLRS1 gene and the phenotypic expression of the disease.