Identification of XLRS1 gene mutation (608C > T) in a Portuguese family with juvenile retinoschisis.
OBJECTIVE
To characterize electroretinogram (ERG) and molecular genetic findings in a family with XLRS1 mutation. The authors present two cases of a Portuguese family with juvenile retinoschisis with a mutation in exon 6.


METHODS
Two brothers and their parents, grandmother, and uncle underwent a full ophthalmic examination. The two brothers with ophthalmic disease were evaluated with color fundus photography, fluorescein angiography, optical coherence tomography (OCT), molecular genetic study (Group VI of Retinoschisis Consortium), pattern visual evoked potential (PVEP), and full field ERG.


RESULTS
Both patients presented funduscopic manifestations of vitre o retinal degeneration. They presented peripheral schisis and retinal detachment. However, foveal schisis had never been observed at funduscopy. A negative ERG was recorded in both. Six months after that, the younger brother showed a typical foveal schisis at fundus examination. A retinoschisis gene (XLRS1) mutation with transition of cytosine by thymine at position 608 (608C > T) had been identified in both.


CONCLUSIONS
Negative ERG is the most secure clinical marker to establish the diagnosis of juvenile retinoschisis. XLRS1 gene 608C > T mutation was described for the first time in a Portuguese family.
Teixeira
C
C
Department of Ophthalmology, Hospital de S. João Hospital, Porto, Portugal. ccg.teixeira@netcabo.pt
Rocha-Sousa
A
A
Trump
D
D
Brandão
E
E
Falcão-Reis
F
F
D002648:Child; D002675:Child, Preschool; D004596:Electroretinography; D005074:Evoked Potentials, Visual; D005091:Exons / Q000235:genetics; D005136:Eye Proteins / Q000235:genetics*; D005451:Fluorescein Angiography; D006801:Humans; D008297:Male; D010375:Pedigree; D017354:Point Mutation; D011174:Portugal; D012160:Retina / Q000503:physiopathology; D041441:Retinoschisis / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology; D041623:Tomography, Optical Coherence
D005136:Eye Proteins; C108726:RS1 protein, human