Chorioretinal Coloboma in Juvenile X–linked Retinoschisis

Abstract

Abstract: : Purpose: To describe an unusual family with XLRS1 gene mutation manifesting morning glory coloboma. Methods: Two male siblings were evaluated for poor visual acuity. Fundoscopic examination was used initially to assess retinopathy. DNA sequencing of the chromosome Xp22 was used to confirm mutation of the XLRS1 gene in the siblings. Results: DNA sequencing analysis revelaed that both siblings had the same N to K change in exon 4 of the XLRS1 gene on chromosome Xp22. The older boy exhibited classical findings associated with X–linked retinoschisis inlcuding bilateral foveal schisis, vitreous veils, and temporal peripheral bullous schisis. The younger child exhibitied a morning glory coloboma in the left eye with no expression of the X–linked retinoschisis phenotype in either eye. Conclusions: Mutations in the XLRS1 gene may affect embyronic differentiation that can lead to colobomatous change, rather than present with the typical cystic changes and schisis cavities of classic X–linked retinoschisis.

Keywords: retinal degenerations: hereditary • genetics • optic disc