Clinical features of X linked juvenile retinoschisis associated with new mutations in the XLRS1 gene in Italian families
- F Simonelli1,
- G Cennamo1,
- C Ziviello2,
- F Testa1,
- G de Crecchio3,
- A Nesti1,
- M P Manitto4,
- A Ciccodicola5,
- S Banfi2,
- R Brancato4,
- E Rinaldi1
- 1Department of Ophthalmology, Seconda Università di Napoli, Naples, Italy
- 2Telethon Institute of Genetics and Medicine (TIGEM), Italy
- 3Department of Ophthalmology, Università Federico II, Italy
- 4Department of Opthalmology, HSR Università di Milano, Italy
- 5Institute of Genetics and Biophysics “A Buzzati-Traverso” (IGB), Italy
- Correspondence to: Francesca Simonelli, Piazza Leonardo, 14 Napoli, 80129, Italia; franctes{at}tin.it
- Accepted 13 December 2002
Abstract
Aims: To describe the clinical phenotype of X linked juvenile retinoschisis in eight Italian families with six different mutations in the XLRS1 gene.
Methods: Complete ophthalmic examinations, electroretinography and A and B-scan standardised echography were performed in 18 affected males. The coding sequences of the XLRS1 gene were amplified by polymerase chain reaction and directly sequenced on an automated sequencer.
Results: Six different XLRS1 mutations were identified; two of these mutations Ile81Asn and the Trp122Cys, have not been previously described. The affected males showed an electronegative response to the standard white scotopic stimulus and a prolonged implicit time of the 30 Hz flicker. In the families with Trp112Cys and Trp122Cys mutations we observed a more severe retinoschisis (RS) clinical picture compared with the other genotypes.
Conclusion: The severe RS phenotypes associated with Trp112Cys and to Trp122Cys mutations suggest that these mutations determine a notable alteration in the function of the retinoschisin protein.
