X-Linked retinoschisis associated to a novel intragenic microdeletion: case report.

Background: X-linked retinoschisis is a recessively inherited retinal degeneration. Clinical diagnosis can be challenging due to the highly variable phenotypic presentation. Also, clinical diagnostic tests may be normal at early stages of this condition. Therefore, genetic diagnosis has become a priceless tool in the management of this disease.
Case Presentation: We present a case of a 17-year-old caucasian male with foveal and peripheral schisis, along with Mizuo-Nakamura phenomenon. RS1 sequencing led to the discovery of an in-frame deletion not previously described in the literature.
Conclusions: Genetic deletions causative of X-linked retinoschisis are quite rare, since more than 80 % are caused by misssense mutations. In this particular case, its pathological effect comes from affecting a key element of the retinoschisin, the discoidin domain.