Clinical features of X linked juvenile retinoschisis associated with new mutations in the XLRS1 gene in Italian families.
OBJECTIVE
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.


CONCLUSIONS
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.
Simonelli
F
F
Department of Ophthalmology, Seconda Università di Napoli, Naples, Italy. Telethon Institute of Genetics and Medicine (TIGEM), Italy. franctes@tin.it
Cennamo
G
G
Ziviello
C
C
Testa
F
F
de Crecchio
G
G
Nesti
A
A
Manitto
M P
MP
Ciccodicola
A
A
Banfi
S
S
Brancato
R
R
Rinaldi
E
E
D000328:Adult; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D004596:Electroretinography; D005136:Eye Proteins / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007558:Italy; D008297:Male; D020125:Mutation, Missense / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D041441:Retinoschisis / Q000235:genetics* / Q000473:pathology
D005136:Eye Proteins; C108726:RS1 protein, human