Lack of association of the Norrie disease gene with retinoschisis phenotype

Purpose: It has been reported recently that mice carrying a disrupted Norri e disease gene produced alterations in the murine eye that are similar to c ongenital retinoschisis. Therefore, it was of interest to determine whether mutations in the Norrie disease gene can account for the disease in famili es with retinoschisis that do not carry mutations in the retinoschisis gene . Methods: The patient set comprised 5 cases of retinoschisis (1 familial and 4 sporadic), all unrelated to each ether. Fundus examination of affected i ndividuals showed foveal and peripheral schisis, and the visual acuity rang e was 20/40-20/60. Peripheral blood specimens were collected from affected and unaffected family members. DNA was extracted and amplified by polymeras e chain reaction amplification of exons of the Norrie disease gene. The amp lified products were sequenced by the dideoxy chain termination method. Results: The data revealed no disease-specific sequence alterations in the Norrie disease gene. Conclusion: Although we cannot completely exclude the possibility of the No rrie disease gene as a candidate gene, the above results suggest that the s tructural and functional changes in the Norrie disease gene are not associa ted with clinically typical retinoschisis families that do not contain muta tions in the coding regions and splice sites of the retinoschisis gene. (C) 2000 Japanese Ophthalmological Society.